Jo Swinson has urged the Jewish community to back her "long-term project taking on populism and nationalism" by supporting the Liberal Democrats.
Dismissing suggestions that her party was heading for a dire result in Thursday's General Election, the Lib Dem leader told the JC: "I am fearful that many of the things we have taken for granted in terms of equality, that we thought were banked, that were safe, now feel under threat.
"I know the Jewish community feels that way, I can understand that.
"There is a long term project or job to be done - which is about taking on populism and nationalism."
Ms Swinson made her plea from the Lib Dem campaign bus at the end of a gruelling week in which national opinion polls had placed the party a distant third behind the Tories and Labour.
But she gave little hint of feeling downcast - and instead spoke about the prospect for Lib Dem candidates in north London, claiming a new band of Jewish voters would turning to her party.
"We don't know what will happen on Thursday," she said. "The choice between either Boris Johnson or Jeremy Corbyn is so unappetising.
"Many people still do look upon both these options with dismay.
"I think the Conservatives are calculating that many people will be so afraid of Mr Corbyn, they will hold their nose and vote for Boris Johnson."
Stressing her belief that like Mr Johnson, Mr Corbyn was "totally unsuitable" to be Prime Minister, Ms Swinson said she was "really cheered" the backing her party was receiving in north London seats Finchley and Golders Green and Hampstead and Kilburn.
"We have an opportunity to make a real breakthrough," she said.
"Look at Finchley, Margaret Thatcher's old seat, people are really taking Luciana Berger to heart.
"She is a first-class candidate and I am very hopeful she will become the MP in the seat."
Ms Swinson said she was dismayed that some in the Jewish community had suggested Ms Berger was wrong to stand against Tory candidate Mike Freer because he was seen as the community's friend.
"It is hugely important that people have a choice," she said. "The idea that people shouldn't put themselves forwards for public service is bizarre.
"Luciana is thoughtful, principled, such a valued member of my team.
"She has been an excellent parliamentarian for nearly a decade and now she is offering herself to serve the people of Finchley and Golders Green.
"Call me biased, but I think the people in that constituency are lucky to have someone like her offering to represent them."
In the midst of a long day campaigning in Hampshire, Ms Swinson struggled to recall the finer details of an Early Day Motion she signed opposing 'excessive' Israeli military strikes in Gaza.
But she said: "I want to see two states, Israel and Palestine living side by side and prospering.
"Like any MP constituents get in touch and ask for support with EDMs. If I do not see anything problematic I will support them.
"My belief is that, if we can have any influence over issues in the Middle East, it is through diplomacy.
"I want to see a two-state solution, which is what I believe most people want to see."
She also stressed the importance of being accountable to among the public and though the media, after Mr Johnson refused to be interviewed by the BBC's Andrew Neil, as four other party leaders were.
"Part of that is out on the doorsteps meeting and speaking with the general public," she says.
"And then it is through the media, newspapers like the Jewish Chronicle, and on television interviews with people like Andrew Neil.
"I am proud to able to engage with the media, with the public. Not everyone is going to agree with me - but that's politics."
Ms Swinson did not dispute that Thursday's election may come too early in her project to rejuvenate her party.
"I'm four months into being leader of the Lib Dems," she said. "There's still a whole lot more to do. When the election was called I was still at the point of recruiting key members my team.
"It's what it has to be. It got to the stage where we had 19 Labour MPs who voted for Boris Johnson's Brexit deal and we weren't able to secure a People's Vote.
"To stop that deal going through a General Election seemed the only possible outlet. We were dictated by that really."