Had the Liberals fallen, the choice between capital and labour would have been much starker - we would have had old-style conservative narrow nationalism on one side and anarchic socio-communism on the other. Some have argued that would have meant industrial and economic strife at best and civil war at worst.
Well, Britain would have continued to decline ITTL and be surpassed by every single major developed economies. Worse, not only Germany and Japan, but also France and even
Italy would have surpassed Britain. All of them experienced over 5% average GDP growth between 1950 and 1970, and for Japan, it even reached 10% during the 1960s. The decline would reach a point where Thatcher Revolution would be the only solution.
IOTL, Britain remains Europe's premier economic power since the end of the First World War.