Shimon Peres skipped the kosher main course at the Zionist Federation gala dinner to dine at a central London Japanese restaurant, the JC understands.
The former Israel president - who is believed to have been paid a six-figure sum to attend last week's fundraiser - left immediately after conducting an on-stage interview with an Israeli-Arab journalist in front of the 900 guests.
The interview took place before the Tony Page-catered main course was served.
Many guests, who had paid £250 for a ticket, mistakenly assumed that the 91-year-old Mr Peres was too fatigued to remain until the end of the dinner, at the Grosvenor Hotel.
But the ZF and Mr Peres's office have confirmed that it had been arranged in advance that he would leave after the interview.
His early exit has been condemned as disrespectful by a senior communal leader, who wished to remain anonymous.
He said: "People paid £250 for a ticket, but Shimon Peres and his entourage disappeared before the main course. You pay someone a six-figure-sum to attend an event, and then he goes off to a non-kosher Japanese restaurant. [Mr Peres' office] even got the ZF to book them taxis there. The ZF volunteers were deflated, to put it mildly."
He added: "Israelis come here and they are very dismissive of us - they see us as a cashpoint. It is in extremely bad taste."
But ZF Chairman Paul Charney - who would not confirm how much Mr Peres was paid, or how much was raised from the event - said: "After his speech, Shimon Peres was always going to leave - that was always the agreement. There are no issues whatsoever. Everything was in accordance with the contract."
He confirmed that the ZF had to re-book hotels in London for Mr Peres and his entourage "a couple of times. Security has to approve a booked hotel and they went and changed it a few times - they did not feel it was right," he said.
A spokesperson from Mr Peres's office - who denied that the former president had changed hotels - said Mr Peres's fee would go "towards social projects, education and sport as part of the Peres Centre for Peace. All the money he earns delivering lectures around the world goes towards this".
She added: "Shimon Peres loves and admires the British Jewish community - he feels close to them. He had a wonderful time in London with wonderful people and old friends."
Asked whether he would have liked Mr Peres to have stayed for the main course - a "sweet chilli shoulder of lamb" - Mr Page said he was informed from the start that Mr Peres would leave before it was served.
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