The Heath Premiership (1977-1986, won 1977, 1982)
The Heath Premiership came to power as Labour fractured, with the breakaway "gang of four" forming the left-wing "British Socialist Party" (over Labour's reply to the industrial unrest and economic turbulence during their time in power). Whilst not admitting any new territories to the United Kingdom, unlike several of his predecessors, Heath is credited with causing fewer constitutional updates then Callaghan, but arguably of greater impact. The 1970s had made clear the impact of Commonwealth economic integration - there was little to be found. Commonwealth nations across the globe were rapidly moving away from imperial trade towards regional trade. Britain's trade with the larger Dominions had fallen off a cliff; Australian trade with the USA had been rapidly growing, and even in the 1960s Australia-US bilateral trade exceeded Australia-UK bilateral trade. Canada and the USA had already signed the Automotive Pact, with growing economic links, and the US already counted for 2/3 of Canada's external trade. Correspondingly, the European Free Trade Agreement, signed in 1960, had reduced trade barriers across many European countries, and stimulated trade between Britain and it's geographically closest neighbours. Even though trade had continued to improve Britain's economy, growth had not been as fast as within the European Economic Community (despite the UK now having integrated close to a million extra citizens across the overseas regions), and to Heath it seemed that Britain needed Europe to try and aid the economic recovery after the turbulence of the 1970s.
Heath's first actions were more domestic minded though, as an almost reflex action to the actions of coal mining unions in the 1970s. As part of a multi-faceted move, Heath was to authorise a programme of new nuclear power construction. This would draw upon French technical assistance, further improving Anglo-French relations to "smooth" Britain's EU accession plan, whilst also reducing the power of the coal unions by substantially diversifying power generation away from coal. With the price of oil and gas and record highs following political instability in the Middle East, nuclear power would hopefully allow Britain to export much of the oil and gas now coming out of the North Sea, improving Britain's economic position - especially after the 1979 oil crisis as Iran moved towards Islamic government. Many of the existing nuclear sites were reused; several had older reactors which either generated little power, were dual purpose for Britain's former nuclear weapons programme (now out of date due to the Polaris agreement with the United States), or were coming towards the late stages of their operational life, whilst one smaller one ended up - in controversial circumstances in the Maltese Assembly - situated on the grounds of the RAF Hal Far in Malta, for whom the Royal Air Force has just closed the base to concentrate all assets at RAF Ta Kali. Malta still uses the plant, generating over two thirds of it's electricity by nuclear and the plant laid the foundations for the closing of the coal-burning power stations, although it's future is in doubt given changes in public opinion.
Britain's application to the European Economic Community in 1978 was received with interest in Europe, who were already in the midst of studying Greece's application, and was immediately followed by applications from the Republic of Ireland, Denmark and Norway who had close links with Britain. Negotiations and alignment continued throughout 1979 and 1980, progressing rapidly - and faster then Spain & Portugal due to their transition from military rule and poorer economic state, until later in the year other foreign global events started to take precedence. The first was an attempted coup in Grenada, following the "Black Power Revolutions" in Trinidad & Tobago, and this was followed by an invasion of the Falkland Islands by Argentina. Whether the timing was a coincidence or opportunistic by Argentina was not clear at the time, but later found to be mostly co-incidental.
The action in Grenada was easier to solve; HMS Bulwark by chance was on the way to British Honduras anyway with an array of troops of the Royal Marines; they were rapidly redirected to Grenada to restore order in collaboration with the local police force. The events in Grenada actually had the opposite effect intended by the revolutionaries on many of the UK West Indies islands, in demonstrating that democracy was not to be taken for granted. The effects of UK membership were evidently on show; a rapid force to reinstate law & order (by chance or not), having a stabilising effect on the islands, and thereby further cemented support for UK membership if there had been doubt before. Unfortunately it also had an impact in Great Britain, helping cement racist views that "white people brought democracy, law & order" and similar views, empowering some right-wing groups in the 1980s.
The second issue, in the South Atlantic, was more difficult to sort, and took 24 hours of rapid discussions at the top level of Westminster as to potential actions. As some put it "what's the use of having a military if we don't use it, and what good will a defence agreement with the UK be if the UK does not uphold it?", underlining the belief that no action would undermine every other defence pact the UK had if it did not uphold the defence of a British territory. As it turned out, the Argentine move swiftly conquered the Falkland Islands, but was predicated on the assumption that Britain would not care about tiny islands at the opposite end of the Atlantic, well away from any strategic areas and minimally populated. They could not have been more wrong as it turned out.
British deliberations eventually settled on a plan for action, not inaction regarding the Falklands. A rapidly assembled carrier strike group, based around the HMS Prince of Wales aircraft carrier saw the flotilla set sail for the South Atlantic. After a long sail south, the group reached the South Atlantic. The use of new airborne early warning and control after a period of time lacking such facilities following the abolition of the Gannet AEW.3 craft allowed Fleet Air Arm fighters to largely repulse any Argentinian efforts to locate and target the Royal Navy ships, whilst strike missions targeted the airport on the Falklands itself, restricting Argentinian planes to operating out of mainland Argentina. The complete denial of Argentine air power by the Royal Navy further cemented the role of carrier based power projection in the UK, and the difficulty in supplying the Falkland troops by Argentina made it a swift recapture of the islands by the United Kingdom. The utter defeat of Argentina led to the swift downfall of the Argentine junta, whilst reinforcing Britain's position in the world, and securing the value of the defence treaties which Britain participated in.
With one eye continuing on European Community membership, Heath's government continued negotiations. By 1981, all issues had been resolved, despite the UK's large grievances over the fledgling European Fisheries Policy. The election of 1982 was largely fought over the very topic of European membership., with Heath winning re-election on his manifesto commitments (and off the back of victory over Argentina), and seeing the UK (along with Ireland, Denmark, Spain and Portugal) joining the European Community in 1986. Crucially, the admission of both the UK and Spain allowed Heath to use European law to force Spain to open the border with Gibraltar. The telecoms dispute had been largely worked around to Spanish frustration, by integrating all the UK overseas regions in to the UK +44 numbering plan, which made it difficult for Spain to block telecoms calls to British-numbered Gibraltar without cutting off telecoms to the entire of the United Kingdom. Likewise, as Gibraltarians now held a full UK passport, they could not be easily discriminated against without disadvantaging all UK travellers to Spain. European Community law mandated the equal treatment of all European citizens, and thus de facto forced Spain's hand; Spain continue to claim Gibraltar, but in reality could do little about it. UK membership of the European Community also began to ease another burning issue in the United Kingdom; that of Northern Ireland. The presence of both the United Kingdom and Republic of Ireland in the European Community and thus the Customs Union meant that border between the two Irish jurisdictions became a lot more open, with no customs border or checks required. Tensions continued to simmer, but at a far lower level then previously seen.
Integration in to the UK also continued in the West Indies. The introduction of British taxation to the islands caused a shock - especially the new Value Added Tax, but the provision of publicly funded services and investment in to the islands brought new funding to the islands. Renovation of the main airport in Barbados began in Heath's post-war period as Prime Minister, serving a dual purpose as the key aviation hub in the British Caribbean, whilst also being a principal military base for both the Royal Air Force and Royal Navy in the aftermath of the Grenada affair. The integration of the West Indies to the United Kingdom also presented an element of regional integration; for the first time it produced full freedom of movement for citizens, and also freedom of movement for business and goods. With full integration, West Indies produce began to appear more frequently in UK shops, whilst a small trickle of people began to migrate, enticed by British universities & further education, or just the prospect of better jobs and wages.
Heath would be the first Prime Minister since Churchill not to welcome any new territory in to the United Kingdom; the focus was firmly on integrating what had already been accepted. Malta and Gibraltar were also integrated in to the UK-Irish Common Travel Area, allowing for passport-less travel between the UK (or Ireland) and both the Mediterranean regions, which further encouraged holiday travel with Malta becoming a firm British favourite for family holidays. Territory continued to slip away from the British Empire however; Zimbabwe (former Rhodesia), Vanuatu, Solomon Islands, and several other smaller Pacific island territories gained independence. Fiji was a notable case; it applied to the UK Government for integration given it's inability to square Indo-Fijian demands for equality with ethnic Fijian fears of domination and losing their lands. Fiji was, however, far to far from Great Britain to be integrated in any realistic fashion; over 10,000 miles apart and roughly 12 hours ahead, making the territory about as far from London as it could be before closing in from the other side of the globe, and so eventually gained independence in 1985. Heath was also the first Prime Minister to visit China (People's Republic of), where initial discussions began over the future of Hong Kong - much of the territory being under a lease which would expire in 1997.
Heath would be undone by 1986 though, being 70 years old and looking increasingly frail against a rejuvenated Labour opposition who were now a solidly centre-left party (with the far-left elements now forming the Socialist Party). By election day, Heath was increasingly seen as a liability before a Conservative loss. When that result came through, Heath's time in politics were largely over as he handed over the reins of the Conservative Party to new blood and waved goodbye to Number 10.
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Notes:
I pondered this chapter for a long time, and would like the keep the world somewhat recognisable from OTL. So Heath has become PM and led the UK in to the EEC/EU (although later than OTL, when the lack of trade partners was really beginning to show as the empire unwinds), and been a bit more successful as PM - a bit later then OTL, but still only makes him 61 when he is PM.
The nuclear plants were based on the idea of the Tories wanting to crush the ability of the coal miners to disrupt the entire country, Thatcher's "a nuclear plant a year" strategy, and the Heath's desire for a closer relationship with France, so I'd imagine these nuclear plants closely resembling France's P4 reactors. Given Malta's prior dependence on coal, and continuing dependence on gas, it seemed an obvious step for a UK-integrated Malta.
I looked long and hard to see if I could use a different war to the Falklands, but there are few territorial claims in the Pacific, the Caribbean and Med islands are either independent or UK-integrated. The Falklands is one of the few where there is a right-wing nationalistic junta making firm claims over a British territory which is a long way away from any British interests and so conceivably would invade despite British power.
Intrigued to see where it goes 