One in three MPs are still undecided on whether Britain should leave or remain in the European Union, according to a new poll out today from Ipsos Mori.
The pollsters carried out the survey for the UK in a Changing Europe think tank, finding that a third of MPs said their vote in the referendum would depend on Prime Minister David Cameron's renegotiations.
One in five Tory MPs told the pollsters they would back Brexit regardless of the outcome of the renegotiation – nearly twice as many as those who said they would vote for the UK to remain in the EU. Another 200 Conservative MPs said they were still deciding how they would cast their ballots.
Including all other political parties, Ipsos Mori found that half of all MPs would vote to remain in the EU and just over one in 10 would vote to leave.
"This research underlines that the PM has it all to play for when it comes to ensuring his own MPs vote with him in the upcoming referendum," said UK in a Changing Europe director Professor Anand Menon.
The results come as Cameron faces crunch negotiations with EU officials ahead of the European Council meeting later this month.
Cameron met with European Council president Donald Tusk for a working dinner in Downing Street last night, but while Number 10 said the meeting was "productive", Tusk tweeted late last night: "No deal yet. Intensive work in next 24 crucial."
The Prime Minister's official spokeswoman said this morning that there had been a "breakthrough" on the issue of the so-called emergency migration brake at the working dinner. But she added there was "a lot still to do" and said "there will be a lot of hard work getting all the other member states signed up to what we need".
Downing Street officials are meeting with European Council and European Commission officials in Brussels today. Tusk is expected publish a draft agreement for the EU reform deal tomorrow. The draft agreement would need to be approved by all 28 EU member states in order to be implemented.