A majority of voters want to change the way MPs are elected, according to a new study.
The British Social Attitudes survey found that for the first time, most people want proportional representation instead of first past the post.
Support for PR now stands at 51 per cent, compared to 44 per cent who want to retain the present system.
In 1983, when the survey was first carried out, support for ditching first past the post stood at 39 per cent.
The survey also found that for the first time, a clear majority of Labour supporters - 61 per cent - now back PR, up from just 27 per cent in 2011.
The findings put pressure on Keir Starmer ahead of next week’s Labour conference, where delegates are expected to vote in favour of calls for the party to dump its support for first past the post.
More than two-thirds (69 per cent) of Lib Dems back PR, which is their party’s official policy.
Elsewhere, the survey also found that support for Scottish independence has more than doubled in the past 10 years, with 52 per cent of Scots now wanting to leave the United Kingdom, compared to 23 per cent in 2012.
And for the first time, fewer than half - 49 per cent - of people in Northern Ireland supporting remaining in the UK.
The survey, which was carried out by the National Centre for Social Research, also found that support for breaking up the UK had risen among those who voted Remain in the Brexit referendum.
Sir John Curtice, senior research fellow at NatCen, said: “More people than ever want to change the voting system in Westminster, support for leaving the UK has also grown in Northern Ireland, and supporters of the major parties in Scotland and England are more polarised than ever over the question of how Scotland should be governed.
“Not least of the reasons for this is Brexit, which seems to have helped fuel partisan disagreement about the country’s constitution.
“Some Remain voters appear to have reacted to being on the losing side in the EU referendum by now wanting to change the rules under which the UK is governed.”