When Ed Miliband headed to Hendon to host a public question-and- answer session in January, there was one issue on the audience's mind.
The man hoping to be Prime Minister was repeatedly pushed to defend his stance on Israel by Jewish constituents who vowed never to vote for Labour while he led the party.
Mr Miliband's position has been under the spotlight since he described Israel's actions during last summer's Gaza conflict as "wrong and unjustifiable" and then attempted to whip his MPs into voting for Palestinian statehood.
In Hendon, where Jewish voters make up 17 per cent of the electorate, this single foreign-policy issue could be decisive in May's election.
It is one of the country's most marginal constituencies. Five years ago Conservative Matthew Offord won the seat with a 106 majority from Labour's Andrew Dismore, who had been the MP for 13 years. Both men are standing again and are acutely aware of the potential impact of their party leader's positions on Israel.
Hendon
Location: North-west London
Sitting MP: Matthew Offord (Con)
Majority: 106
Size of electorate: 74,329
Percentage of Jewish voters: 17.0
Also standing in May: Andrew Dismore (Lab), Alasdair Hill (Lib Dem), Ben Samuel (Green), Jeremy Zeid (Ukip)
Dr Offord said: "I had people at that meeting saying how badly Miliband came across. People do not forget his comments about Gaza, where he completely undermined Israel.
"They are saying: 'I always vote Labour, but not in this election because of Miliband's stance'.
"David Cameron has always been a friend of Israel. I am prepared to stand up for the issues that are important to my constituents. I've always been an advocate for Israel and the country's right to exist in peace and security.
"I don't think many Labour MPs believe that. I don't think they want Israel to exist in its current form, I don't think they want it to be the Jewish homeland."
While Mr Dismore is keen to emphasise his party's policies on the health service, policing and housing, he recognises the effect Mr Miliband's stance on Israel has on his campaign.
"I have a difference of view with Ed on Gaza," Mr Dismore said, referring to Operation Protective Edge. "I didn't see Israel as having much other option at the time.
"People have a knee-jerk reaction and think Ed is anti-Israel. He's not, no way. To say Ed is anti-Israel is to say that roughly half the Jewish population of Britain is anti-Israel, because they had views that are not dissimilar. It was an issue that divided the community here and in Israel. Is Israel the only thing that matters to Jewish people in Britain? Or are they concerned about domestic Jewish affairs, where I think my and Labour's record is a very good one."
Mr Dismore cited the importance of community building and social justice as examples of values shared by Jews and Labour.
Both candidates outlined their commitment to combating antisemitism, protecting shechita and funding Jewish education.
Dr Offord said the Conservatives would increase funding for security at independent Jewish schools and cultural sites such as JW3.
"People are concerned about their personal security," he explained. "The perception and fear of antisemitic behaviour in the minds of many of my Jewish constituents is very real."
But Mr Dismore said pushing for such additional money was wrong when government cuts had led to a reduction in local police forces.
"There are now 69 fewer police officers in Barnet - an 11 per cent cut. I think that is a concern for the Jewish community in particular," he said. "The Community Security Trust, as wonderful an organisation as it is, can only do so much. You have got to have the Metropolitan Police back-up when things go wrong. Labour would protect the front line of policing."
The pair do not get on following a highly fractious campaign five years ago. Politics in Hendon spilled over into the personal - with Mr Dismore describing Dr Offord as a "bully"; and the Tory claiming his opponent had refused to shake hands. A similar campaign is expected this time.
"It's a tight contest, I don't pretend otherwise," said Mr Dismore.
Dr Offord said: "I think there might be an assumption among some people that Labour will just walk in because we had a small majority. I can assure you that's not going to happen. I remain confident, but certainly not over-confident or complacent."
There is now an additional threat to both men - the growing support for Ukip and the Green Party. Both leading candidates could lose voters to the smaller parties. The one who's most successful in hanging on to his traditonal support base will almost certainly find themselves victorious come polling day.
Dr Offord has been unpopular with his own local Conservative branch members, while Mr Dismore knows the concerns over Israel policy could hurt him.
● Liberal Democrat candidate Alasdair Hill is working hard to retain the 12 per cent of voters his party attracted in Hendon five years ago.
A science teacher, he backs his party leader Nick Clegg's belief that Israel's reaction in Gaza last year was "disproportionate".
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