Ladbrokes has reported dramatic movements in money being placed on this week's referendum, with more and more punters minded to back the Remain camp.
The bookie is now offering odds of 3/10 on the UK opting to stay within the EU, equivalent to a 73 per cent chance of Remain winning.
By contrast, the odds of a Leave vote are now 5/2, giving a 27 per cent chance of Brexit.
With just days to go before Britain votes, the figures represent an 11 per cent swing towards Remain since last week, when bookies were offering their shortest ever odds on a Leave vote.
Ladbrokes' head of political betting Matthew Shaddick said: “There’s been a significant shift in the odds back towards Remain. Looking closely at the figures, the proportion of money being placed on Leave hit its peak a couple of weeks ago.
“The picture certainly looks significantly different to last Monday.”
It comes as Betfair also reports an increased likelihood of a Remain vote, with the implied probability of the UK retaining EU membership rising from 65 per cent to 72 per cent.