What the title says. Here's how I think they would turn out. I'll note the OTL results for comparison.
1964 - Wilson demolishes Home with ease. Labour win a majority of around 50 (OTL: Labour won a majority of 4).
1966 - Wilson is widely viewed as having defeated Heath, although the latter is clearly a superior debater to Home. A Labour majority of around 120 (OTL: Labour won a majority of 96).
1970 - Heath really digs into Wilson over devaluation and his failure to get Britain into the EEC. The debate is seen as a draw, and doesn't have much impact. Labour are still expected to win, but the Tories end up winning with a similar majority to OTL - around 30.
February 1974 - Jeremy Thorpe becomes the first Liberal leader to be allowed into the debates. He positions himself as a moderate and implies that the Labour and Conservative parties are dangerous extremists. The Liberals end up with around 25% of the vote and 50 seats (compared to 19% and 14 seats in OTL). Labour and Liberals form a coalition government (OTL: Labour were just the largest party and formed a minority government).
October 1974 - Probably ditto (OTL: Labour won a majority of 3).
1979 - Callaghan comes across as a kind uncle, Thatcher comes across as aggressive and lightweight. Steel does well enough to improve his party's poll numbers. Hung parliament, perhaps with Labour as the largest party by a handful of seats. Another election within two years (OTL: The Conservatives won a majority of 43).
1983 - Foot is articulate but doesn't really look the part. Thatcher wins. Steel does well but not enough to have a meaningful impact on the opinion polls. Not much different to OTL - Conservative majority of somewhere around 144, give or take a handful of seats.
1987 - Thatcher wins again. Kinnock enters the debate with confidence but ends up looking foolish. Steel does his usual - good but not very impactful. Perhaps a slightly bigger Conservative majority than in OTL - around 120 compared to 102.
1992 - Major is boring, Kinnock blathers on too much. Ashdown comes across as the most Prime Ministerial. The Lib Dems end up doing about 5 percentage points better than OTL - 22-23%. Perhaps enough to wipe out the Conservative majority, which was 21 in OTL.
1997 - Blair and Ashdown rip into Major. Major holds his ground fairly well. Labour's victory is on a similar scale to OTL - 179 or so. The Lib Dems perhaps win a few more seats from the Tories due to Ashdown's impressive debate performance.
2001 - Hague wins this. Blair visibly feels the pressure after Hague slams Labour's record on public services, Europe and immigration. Kennedy criticises Blair from the left. But none of this is overwhelming enough to prevent another Labour victory - they end up with a majority of around 110 (OTL: 167).
2005 - Howard isn't as good as Hague, but he's seen as the debate winner. Kennedy again attacks Blair from his left and picks up a handful more seats from Labour. Labour majority of around 40 (OTL: 66).
1964 - Wilson demolishes Home with ease. Labour win a majority of around 50 (OTL: Labour won a majority of 4).
1966 - Wilson is widely viewed as having defeated Heath, although the latter is clearly a superior debater to Home. A Labour majority of around 120 (OTL: Labour won a majority of 96).
1970 - Heath really digs into Wilson over devaluation and his failure to get Britain into the EEC. The debate is seen as a draw, and doesn't have much impact. Labour are still expected to win, but the Tories end up winning with a similar majority to OTL - around 30.
February 1974 - Jeremy Thorpe becomes the first Liberal leader to be allowed into the debates. He positions himself as a moderate and implies that the Labour and Conservative parties are dangerous extremists. The Liberals end up with around 25% of the vote and 50 seats (compared to 19% and 14 seats in OTL). Labour and Liberals form a coalition government (OTL: Labour were just the largest party and formed a minority government).
October 1974 - Probably ditto (OTL: Labour won a majority of 3).
1979 - Callaghan comes across as a kind uncle, Thatcher comes across as aggressive and lightweight. Steel does well enough to improve his party's poll numbers. Hung parliament, perhaps with Labour as the largest party by a handful of seats. Another election within two years (OTL: The Conservatives won a majority of 43).
1983 - Foot is articulate but doesn't really look the part. Thatcher wins. Steel does well but not enough to have a meaningful impact on the opinion polls. Not much different to OTL - Conservative majority of somewhere around 144, give or take a handful of seats.
1987 - Thatcher wins again. Kinnock enters the debate with confidence but ends up looking foolish. Steel does his usual - good but not very impactful. Perhaps a slightly bigger Conservative majority than in OTL - around 120 compared to 102.
1992 - Major is boring, Kinnock blathers on too much. Ashdown comes across as the most Prime Ministerial. The Lib Dems end up doing about 5 percentage points better than OTL - 22-23%. Perhaps enough to wipe out the Conservative majority, which was 21 in OTL.
1997 - Blair and Ashdown rip into Major. Major holds his ground fairly well. Labour's victory is on a similar scale to OTL - 179 or so. The Lib Dems perhaps win a few more seats from the Tories due to Ashdown's impressive debate performance.
2001 - Hague wins this. Blair visibly feels the pressure after Hague slams Labour's record on public services, Europe and immigration. Kennedy criticises Blair from the left. But none of this is overwhelming enough to prevent another Labour victory - they end up with a majority of around 110 (OTL: 167).
2005 - Howard isn't as good as Hague, but he's seen as the debate winner. Kennedy again attacks Blair from his left and picks up a handful more seats from Labour. Labour majority of around 40 (OTL: 66).