The outcome of the EU referendum is on a knife edge, a new poll has revealed, with the campaign for Britain to leave gathering momentum.
An ICM survey for the Vote Leave campaign shows support for a Brexit is at 41 per cent, with 42 per cent in favour of remaining in the EU.
It shows support for quitting the EU would rise if David Cameron failed to secure reforms to freedom of movement rules - 45 per cent would vote to leave, with 40 per cent opting to stay in.
When undecided voters are taken out, the poll shows a 50/50 split - the first time ICM has found an even split in more than two years.
It comes as an influential committee of MPs warned voters that there is no guarantee that any reforms won by Mr Cameron's renegotiation would be delivered.
The EU Scrutiny Committee said the Prime Minister's most contentious proposals - making EU migrants wait four years before they can claim in-work benefits - would require EU treaty change, but this would not be achievable before Mr Cameron's deadline of holding a referendum before the end of 2017.
Leading Tory eurosceptic Sir Bill Cash, who chairs the committee, said: "Our poll is clear, the only way in which the Prime Minister's negotiations could be given the legally binding and irreversible effect which he has called for would be through treaty amendment, or the equivalent agreement of a protocol.
"These would be lengthy processes, and each member state would have to agree using its own constitutional procedures including referendums.
"Whatever the promises made in the negotiations, there is no certainty that they will be delivered to the British people.
"Voters in the forthcomiong referendum must be aware of this when they make their choice," he warned.
The ICM poll of 2,053 voters also found that 65 per cent of those describing themselves as "enthusiastic" about the EU referendum were in favour of leaving.
The poll will deal a blow to Mr Cameron ahead of his key summit in Brussels on Thursday and Friday, where he will seek to persuade his fellow 27 EU leaders of the need for reforming Britain's relationship with the EU.
On Monday Foreign Secretary Philip Hammond admitted that none of the 27 leaders had proposed an alternative to Mr Cameron's proposal to restrict benefit payments to EU workers, which has faced widespread opposition from eastern and southern European countries.
It means Mr Cameron will face an uphill task to secure a deal in time to be signed at the next EU summit in February.
However the Government was given a boost on Monday evening when the House of Lords approved the EU Referendum Bill, with a move to give 16 and 17 year-olds the vote in the referendum rejected.
It means the referendum could be held as early as June next year.Reuse content