“Others can make their own views” about Sir Ed Davey’s campaign trail antics, the Liberal Democrat leader has said.

Flipping burgers in a back garden on the campaign trail in Wiltshire, the party leader said he was “really sorry” about a speeding incident which hit the headlines yesterday.

He said his stunts on the campaign trail – which include toppling from a paddleboard into Windermere in the Lake District and speeding down the Ultimate Slip n Slide near Frome, Somerset – come with “very serious” messages.

I’ve shown with some of the photo ops we’ve done – the paddleboard in Lake Windermere – that behind that fun there’s a very serious message

Facing questions about the optics of his campaign trail so far, Sir Ed told the PA news agency: “I think others can make their own views.

“I’ve shown with some of the photo ops we’ve done – the paddleboard in Lake Windermere – that behind that fun there’s a very serious message.

“So, in the Lake District, we were talking about sewage and the fact that the Conservatives have allowed water companies to pump their filthy sewage into precious environments like the Lakes there or our rivers and our beaches and we’re campaigning about that.

“When I came down that slide with those children, that was about mental health – the mental health of our children and young people – which has again been ignored by the Conservatives.”

Sir Ed added: “As for the speeding fine … I was on the M1, I hadn’t noticed that the speed limit had reduced temporarily to 60mph, and I broke the law, and I’m really sorry about that. And I paid the fine.”

Sir Ed was caught travelling at 73mph near Caddington, in Bedfordshire.

When asked about whether the Liberal Democrats had any coalition “red lines”, should no party secure a majority at the General Election on July 4, Sir Ed said: “I’m just not thinking about after the election.”

He said his party had done “so well” at recent local elections and that “people now now Liberal Democrats can win” in places like the West Country and Home Counties.

Sir Ed brushed off speculation that Nigel Farage’s return to frontline politics – standing for Reform UK in Clacton on the Essex coast – could hamper his party’s chances among Conservative and Liberal Democrat swing voters.

“I and the Liberal Democrats don’t share any of the values of Nigel Farage,” he said.

“I’ll let the Conservatives worry about their problems.

“What I’m clear about is our Liberal Democrat ideas on the NHS and care, on tackling the sewage scandal, on the cost of living, they are attracting Conservative voters as well.

“We are finding lots of lifelong Conservatives switching to us. They aren’t really attracted by Nigel Farage’s ideas.”

The Liberal Democrats held their Great British barbecue in Wiltshire on the 80th anniversary of D-Day, attended by ex-service personnel who met Sir Ed.

The party leader told the media D-Day “was a fight for freedom, a fight for democracy, if those brave men and women hadn’t fought that day and gone onto those beaches, we might not be having elections … we might not be having the things we enjoy”.