Seven in 10 MPs think Theresa May has done a bad job of handling Britain's withdrawal from the EU, a new survey has found.
Even 47 per cent of Conservatives think the prime minister has managed negotiations poorly, compared with just 34 per cent who think she has performed well.
The Ipsos MORI poll also found that a majority of Tory MPs believe the difficulty of reaching an agreement with the EU over the Northern Ireland border has been exaggerated.
The findings will come as a fresh blow to Ms May just days before MPs are due to vote on her proposed Brexit deal.
The Commons is widely expected to reject the proposed agreement over widespread opposition to the Northern Ireland backstop, which Tory Eurosceptics fear could keep the UK trapped in a customs union with the EU against its will.
The issue is at the heart of the row over the proposed deal, with ministers insisting that the backstop will be temporary and that there cannot be a withdrawal agreement without one.
However, the poll found that just 30 per cent of Tory MPs think the government is facing genuine problems in finding a solution on the Northern Ireland border, while 55 per cent think the issue has been exaggerated as a negotiating tactic.
Among all MPs, though, 60 per cent think there are genuine difficulties in reaching an agreement on the matter.
The poll was carried out on behalf of The UK in a Changing Europe group at King's College London and the Mile End Institute at Queen Mary University of London.
Professor Anand Menon, director of The UK in a Changing Europe, said: “The House of Commons is clearly very divided. It is hard to see, given the numbers, how the prime minister can get her deal through. That being said, it is hard to see how any outcome can command a majority.”
Queen Mary's Professor Tim Bale said: “None of this will make easy reading for the PM - the attitudes of Leave-voting Tories appear to be hardening rather than softening and they seem amazingly unfazed by the difficulties presented by both the Irish border issue and a no-deal Brexit.”
With speculation rife as to how Ms May will respond if her deal is voted down, a group of MPs from across the Commons is pushing her to pivot to a softer Brexit that would see the UK agree a Norway-style deal to stay in the EU's single market.
The poll found that MPs are more opposed to such a plan than they were 12 months ago. 58 per cent now believe that staying in the single market would not honour the result of the 2016 referendum, compared with 42 per cent who said the same last year.
The change is mostly a result of a shift among Labour MPs, 36 per cent of whom are now opposed to the UK retaining its single market membership - up from 8 per cent last year.
There is more support for remaining in a customs union with the EU, however, with half of MPs saying this would still deliver Brexit.
Ipsos MORI conducted face-to-face interviews with 98 MPs in November and December.
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