Juliet Rosenfeld – the wife of the late Jewish Care trustee Andrew – has revealed she has rejoined the Labour Party after backing Sir Keir Starmer to become leader.

The psychotherapist claimed she “trusted” Sir Keir “completely on the issues that matter” in a report in The Observer newspaper, which suggested Jewish donors who had abandoned Labour under Jeremy Corbyn were now returning.

Prior to his sudden death from cancer in 2013,  Ms Rosenfeld’s late husband had been one of Labour’s most generous backers.

“I voted for Keir and am delighted he has won,” she confirmed.

“He is someone ‘without a side’. I trust him completely on the issues that matter, and I will, and have, encouraged others to come back to Labour.”

Lord Levy, Labour’s leading fundraiser under Tony Blair, was quoted in the same report saying that the party should consider having a mix of funding from private donors and unions.

“It’s very early days, but whereas I would say major donors would have had no interest over this last period, I think there is a real possibility now that they will return to the fold,” he said.

“The party needs to be funded by people who believe in the cause and we need to work closely with the unions. Neither should be mutually exclusive.”

Another unnamed donor, who cited the antisemitism scandal under Mr Corbyn, said: “I would not give Labour money under Corbyn, but I would now be happy to give money to Labour.

“Previous donors need to meet Keir and Angela [Rayner, the deputy leader] and learn to trust them, because the history over the last four years has been horrific.”

Ms Rosenfeld won praise for her book The State of Disbelief, which told of her struggle to deal with her husband’s death just 13 months after he was diagnosed with lung cancer.

Mr Rosenfeld hit the headlines in 2005 after a £1 million loan engulfed him in the ‘cash for honours’ scandal involving Lord Levy.