The European Parliament’s Brexit co-ordinator Guy Verhofstadt backed Liberal Democrat candidates during a campaign visit to Camden this morning.
Making his first stop since arriving in London, he also launched the his own party's "alternative to populism and nationalism."
Mr Verhofstadt said he was visiting as the leader of the liberals and democrats for Europe in the European Parliament, rather than as a Brexit negotiator. He is also an MEP and former Belgian prime minister.
A throng of Lib Dem activists greeted him, along with candidates for London in May 23's election, leader Sir Vince Cable, and Sir Ed Davey MP. Camden councillor Luisa Porritt is third on the party's list for the region.
Speaking while council workers cut the grass nearby, he said: "I think it's important to show that the European liberals and democrats support Vince Cable. Secondly, we want to show by coming here a message to the continent to say never repeat Brexit again. It's clear that Brexit has done far more damage than we ever thought.
"I'm a Lib Dem. It's natural that people are looking to the Lib Dems when it comes to European elections. We want to be the alternative for nationalism and popularism."
He then spoke to one supportive voter in Camden Square, doors away from late-singer Amy Winehouse's former home.
Luisa said: "We're delighted that Guy has come to support us, and he understands how important this election is for us. It's existential. He knows we need the support and that we're the biggest pro-European party in this country."
In a poll conducted by YouGov a fortnight ago, in London the party were 18 points behind Labour in a crowded field of parties backing a second referendum.
The Green Party, the Lib Dems, and Chukka Umunna's Change UK shared 37 points between them.
Cllr Porritt, who was elected to Camden Council last year for Belsize, said she believed the Lib Dems would do well despite the competition.
She said: "We may miss out on getting as many pro-European MEPs as we can, but we're in the best position to capitalise on that remain vote after our strong local election results in London last year."
"We've been a pro-European party for 50 years, and we've always been open and pro-European and internationalist. It's been our policy to have a referendum on Theresa May's deal since the day after the vote in 2016."
The 31-year-old said that the Labour vote in London appears to be weakening as the campaign goes on.
"I've been into strong Labour areas where previously that vote would be impenetrable for us. Areas like Hackney, Islington and Camden. We're finding tha the Labour vote is softening in a way that it wasn't before.
"There are a lot of very disappointed Labour voters, and it's important to express their voice if they voted for remain. I've spoken to people who have been Labour members for years, and it's heart wrenching for them, but they'll be voting for us in this election."
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