The probability of a Remain vote in this week's EU referendum has climbed to 72 per cent, according to Betfair's odds.
The bookmaker's odds show that the implied probability that the UK will vote to stay in the bloc has increased from 65 per cent on Friday.
The figures emerged as Britain prepares to vote on its membership of the EU on Thursday, with campaigning beginning again today, after both sides called off election activities in the wake of the tragic death of Labour MP Jo Cox.
Markets are braced for one of the most volatile weeks of trading since the 2008 financial crisis, with analysts warning that the final run-up to the referendum could see stock markets thrown into chaos.
Meanwhile, a member of the European Central Bank's (ECB) governing council has warned that a vote to leave the EU could threaten the political stability of the union.
"We see the risk of Brexit in three areas: political instability that could occur in countries with strong eurosceptic parties, which could lead to a local political instability," said Jozef Makuch, and cited Spain as an example.
"There is possible instability linked to the speed of integration. There are issues that require a unanimity which would be problematic to reach in case of uncertainty."
Makuch, who is the central bank chief of Slovakia, said the ECB's biggest concern was the potential for market instability, but added that the bank has the tools to reduce volatility, and has done so "many times in the past".