Harrow West has stayed red after incumbent Labour MP Gareth Thomas won a narrow victory, netting 21,885 votes.
He secured a reduced majority of 2,208 over first-time Jewish Conservative candidate Hannah David, who polled 19,677.
UKIP pushed its way to third place with 2047 votes, relegating the Liberal Democrats.
In the 2010 general election Mr Thomas won a majority of 3,143.
The Shadow Middle East Minister, was the first Labour candidate to win the seat when he captured it in the Tony Blair landslide victory of 1997.
Among the Tories who have failed to unseat Mr Thomas since then are Mike Freer, who was re-elected as an MP in Finchley, and Daniel Finkelstein, now a peer.
The Jewish population of Harrow West has dwindled in the past 20 years, but the constituency remains one of the most ethnically diverse seats in the country.
Non-practising solicitor Ms David, who is known in the community for her Borehamwood Let’s Meat restaurant, began her career in politics as leader of the local council..
In a JC interview before the poll, she said: "David Cameron sends a really important message when it comes to Israel. People in the Jewish community are nervous. But with him in control they feel safe."