A poll for Survation on behalf of Better Together puts the no vote on 54 per cent and 46 per cent backing independence for Scotland.
Better Together said the full voting figures were 40.8 per cent yes versus 47 per cent no. Excluding undecided voters, Survation rounded the voting intention to 54 per cent no versus 46 per cent yes.
The telephone survey of 1,044 voters also found that 40 per cent believed they and their families would be financially worse off compared to 27 per cent who believe they would be better off.
The survey also points to a very high turnout with 93 per cent of voters saying they are certain to vote.
Earlier polls showed a narrower margin between the two sides. A Guardian/ICM poll put support for the UK at 51 per cent ahead of 49 per cent for independence, excluding undecided voters, while a Times/Sun/YouGov poll gave No a slightly larger lead at 52 against 48 per cent.
Survation’s last poll on Wednesday showed unionists on 53 per cent and nationalists on 47 per cent.
A online survey of English voters by Populus for the Daily Mail found that only 20 per cent approve of Scottish independence while 70 per cent want to keep the United Kingdom together.
If Scots do vote for independence, 53 per cent of Englosh voters do not believe he should the country should be allowed to keep the pound, with only 26 per cent in favour.
And 61 per cent think Scots MPs should be barred from voting in Westminster on policies which do not apply north of the border.
Only people living in Scotland have the right to cast a vote in the independence referendum on 18 September, but 56 per cent of voters in England said the whole of the rest of the UK should have been allowed to take part.