But when asked how they would vote if it became apparent that the seat was a two horse race on December 12 between the Lib Dems and Tories, Ms Berger came out on top.
On Sunday, polling expert Peter Kellner, a former director of YouGov, wrote in the Observer: "With tactical voting, Luciana Berger has a real chance of winning Finchley for the Lib Dems."
In a further move that appeared designed to damage Ms Berger's chances of defeating Mr Freer, Tulip Siddiq, the Labour candidate for neighbouring Hampstead and Kilburn, was photographed alongside Mr Houston to launch his campaign.
Ms Siddiq has always expressed strong pro-Remain views over Brexit. Local Labour supporters in her constituency were said to be furious with her attempt to split the vote against Mr Freer, who is a government whip under Prime Minister Boris Johnson.
On Monday, Labour candidate Mr Houston said he was “not aware” that Ms Alvarez was joining his campaign team in north Finchley on Sunday
