Stanley Fink, co-treasurer of the Conservative Party, says it remains anybody's guess as to which way the Jewish community will vote at the forthcoming general election.
Mr Fink, who has helped boost the Tories' fortunes since David Cameron became party leader and personally gave the party £1m last year, said: "I suspect the Jewish community will be divided, with a number of people who feel tribally loyal to Labour being offset by a growing number of people who see in David Cameron and the modern Tory Party as a party which shares Jewish family values and is likely to be fairer to Israel."
Dubbed "the Godfather" of the hedge fund industry, Mr Fink is the former chief executive of Man Group. He now runs hedge fund International Standard Asset Management, of which Lord Levy is chairman. He will step aside from his position as co-treasurer after the election.
There has been speculation this week that he would "resign" as co-treasurer in order to take on a top post in a David Cameron-led government, but Mr Fink said no particular role had been offered to him.
"I am co-treasurer with responsibility for this election fighting fund, so technically the job comes to an end on the day of the election."