The UK has become a laughing stock abroad since the vote to leave the EU, the Liberal Democrat leader has said.

Giving a speech to the Institute for Public Policy Research (IPPR) in Manchester on Wednesday, Tim Farron said “malevolent forces” were seeking to hijack the result of the referendum and that the vote had not been an endorsement of Ukip’s politics.

“We’ve been made a laughing stock abroad,” he said. “We’ve had to watch the shaming pictures of Nigel Farage sneering on our behalf in the European parliament.”

Speaking to the Guardian after the speech, Farron said people abroad were increasingly associating the UK with figures like Farage, the former Ukip leader. “When Nigel Farage gets up to speak in the European parliament it’s noticed by very few people here, but it’s noticed by pretty much everybody on the continent,” he said.

Last week, Hillary Clinton, the US Democratic presidential hopeful, condemned her Republican opponent, Donald Trump, for sharing a platform with Farage, whom she described as “one of Britain’s most prominent rightwing leaders”.

“The problem is that that is how we are seen overseas and that’s not something I want for my country,” said Farron, in reference to Clinton’s comments. “If we end up going down the road of Brexit … we do need nevertheless to be a country that is open, outward-facing and utterly engaged with the world.

“We mustn’t allow the faces of Farage, and [foreign secretary Boris] Johnson, [Brexit secretary David] Davis and [international trade secretary Liam] Fox to represent Britain. They don’t.”

The Lib Dems have called on Theresa May to offer the public a referendum on the terms of the UK’s exit from the EU once they have been negotiated, saying one option should be to stay a member.

Speaking to the audience at the Greater Manchester Chamber of Commerce, Farron said a new division was emerging in British politics between the forces of “tolerant liberalism and intolerant, closed-minded nationalism”.

“We are in danger of letting malevolent forces hijack the result [of the referendum],” he said. “Plenty of my mates voted leave and I can tell you that the overwhelming majority of those who did vote leave are utterly appalled that Farage, [Marine] Le Pen and their ilk now seek to claim the result as a victory for their hateful brand of intolerance, racism and insularity. Britain is better than that.”

Le Pen, the leader of France’s far-right Front National, has described the result of the EU referendum as “the most important moment since the fall of the Berlin Wall”.

Speaking at a Trump rally last week, Farage said Brexit had been a result “for the little people, for the real people”.

“We reached those people who have never voted in their lives but believed by going out and voting for Brexit they could take back control of their country, take back control of their borders and get back their pride and self-respect.”