British politics is on a knife-edge today as politicians and the general public await the result of the “meaningful vote” on Prime Minister Theresa May’s Brexit deal.

Few people expect the government to win the vote in the House of Commons, but estimates of the likely scale of the defeat vary enormously.

All six Suffolk Conservative MPs are backing Mrs May’s deal – four of them have government positions – while Ipswich Labour MP Sandy Martin is following his party line and voting against the proposal.

Most Essex MPs are expected to vote against it unless there is a surprising change in the Ulster “Backstop” arrangement at the last minute.

Speaker John Bercow has allowed four amendments to be discussed as part of the debate – that means the final result is expected at some time around 8.30pm after voting starts at 7pm.

Some voting experts – including some Government whips – are predicting that Mrs May could lose by 200 votes. However others think this is damage limitation talk with the defeat more likely to be between 50 and 100. They suggest the government is talking up the scale of the likely defeat in a bid to make a smaller loss look less disastrous.

Labour leader Jeremy Corbyn is expected to table a vote of no confidence in the government if – or more likely when – the deal is rejected by the House of Commons.

That would be tabled tonight and could be debated tomorrow – but the Conservatives are confident that they will be able to defeat any such motion.

All Tory MPs will be whipped to support the government in a confidence motion. Any who vote against it, or even abstain, would be immediately thrown out of the party and would not ever be able to stand as a Conservative in an election again.

If parliament carried on they would have to sit as an independent.

If members of the DUP failed to support the government, the deal with the party after the 2017 election would be torn up – and the benefits that Ulster got from it would immediately cease.