Former Hendon MP Andrew Dismore has rejected claims that an initiative by a Muslim organisation which campaigns against candidates who back Israel cost him his seat.
Mr Dismore, who had held the constituency for Labour since 1997, was defeated by Conservative candidate Matthew Offord by just 106 votes, the second narrowest margin in England.
On its website, the Muslim Public Affairs Committee (MPAC) claimed it had "defeated the top ranking Zionist MP Dismore!".
The MPAC statement said: "Dismore has MPAC and the Muslims of Hendon to thank for his early retirement. We're waiting for his card and flowers.We were planning Andrew Dismore's downfall for a long time and the General Election was our chance to give him both barrels. He didn't like it one bit."
The organisation said Mr Dismore had "squealed to his friends in the Jewish Chronicle" in the hope readers would sympathise with him.
But Mr Dismore said: "I will not give MPAC the credit for defeating me; it's just how it turned out."
He is considering a legal challenge against the result after claiming Barnet Council ran the poll "incompetently". He wrote to supporters asking them to provide evidence of "irregularities" and proof they had been denied the chance to vote.
He also alleged Mr Offord had run a "dirty campaign" and launched personal "slurs and lies.
"It's the most unpleasant campaign I've been involved in - but I don't want to sound like a bad loser," said Mr Dismore. "I want to take stock. It's very traumatic to lose in such a way."
He also said he would "love" to be able to work with Jewish organisations, having built up experience of representing constituents' views on issues of Jewish and Israeli significance while in Westminster.
Mr Offord denied his campaign had been negative. "I went out of my way to acknowledge the work Mr Dismore had done locally. His speech at the count was not very magnanimous. I can't comment on the running of the election. We have had no complaints."
Mr Offord has already contacted Labour peer Lord Janner to discuss issues of importance to Jewish constituents.
Barnet's Acting Returning Officer, Nick Walkley, said: "Barnet did not suffer from the problems that some other boroughs and councils faced. We will be reviewing the whole process."