Liberal Democrats leader Tim Farron addresses supporters in Stockport, Greater Manchester. Adam Payne/Business Insider STOCKPORT — Tim Farron says Theresa May was being "anti-democratic" by refusing to participate in last night's ITV general election debate.

Speaking to Business Insider in Stockport, Greater Manchester, on Friday morning, the Liberal Democrats leader accused Prime Minister May and Labour leader Jeremy Corbyn of insulting the British people for not showing up to the televised debate ahead of the June 8 vote.

"They will regret not showing up for certain," Farron told us.

The Liberal Democrats leader debated issues like Brexit, education, and immigration with the leaders of UKIP, Green Party, SNP, and Plaid Cymru on Thursday evening.

Both May and Corbyn were invited to take part in the debate but declined.

"How dare Theresa May call a general election for the benefit of only Theresa May and then not have the guts to face up to the electorate?" he said:

"These few weeks have been marked by Theresa May running away from anyone normal, refusing to talk to people like you on your terms, and then turning her back on the people when it came to the chance to debate.

"As you will have seen, I am more than happy to put myself into places where I may get asked difficult questions and meet people who don't agree with me. That's what politics should be about.

"I think it's anti-democratic for her to snub last night's debate and snub the British people."

Farron was in Stockport to campaign for Lisa Smart who is vying to win the Hazel Grove seat that the Liberal Democrats lost to the Tories in 2015. Farron's party trails by 15.6% here, and activists admit it'll be tough to win.

It'll be an even bigger ask if the party doesn't improve in the opinion polls. There was talk of a Lib Dem revival heading into the general election, but the party is struggling to surpass 10%. A Business Insider / GfK poll published this week put the Liberal Democrats on 7%, less than the share of the vote it won in 2015 when its vote collapsed nationwide.

However, Farron was upbeat when he spoke to us this morning, talking down the significance of the polls.

"Well, we have had some very positive indicators," he insisted.

"Our membership has shot up to its highest ever. We have over 100,000 members now. We saw in the local elections the Liberal Democrats were the only party to gain vote share. In fact, we put 7% on, which is twice as much as the Tories. Everybody talks about how well the Tories did in the local elections — we did twice as well as they did when it came to increased vote share. And we are the only opposition party who even looks like we are up for this."

He also played down reports that Conservatives in Cumbria are confident of taking his Westmorland and Lonsdale seat. A Tory candidate standing elsewhere in the county told Business Insider that the party is "throwing money and resources" at Farron's seat amid a growing feeling that it could be one the Tories snap up as part of a landslide victory.

"I don't know where they get their information from," he said. "The Liberal Democrats won very comfortably there in the local elections in May. I've always assumed that you take nothing for granted, unlike Theresa May. You borrow your job from the electorate."

"The minute you become arrogant and say things like the Tories are, that's when you deserve to lose."

Farron visited a community cafe in Woodley, a suburb of Stockport, where he spoke to local people about issues affecting the area and wider Greater Manchester region. The Liberal Democrat leader, who was born in nearby Preston, fears a huge Conservative majority will mean a long period of neglect for Stockport and the rest of the North.

Farron speaks to locals at the Startpoint cafe, Stockport. Adam Payne/Business Insider

"It would be totally overlooked," he said. "The more Theresa May wins by, the more she will take you for granted."

"That's obvious by what's in the manifesto. If you thought you had a chance of losing the general election you'd never dream of coming up with something as heartless and appalling as the dementia tax. You'd never go scrapping free school meals for infant children. It's the height of arrogance."

"For you and your community, whether you live, particularly the North of England, I want you to imagine what it will mean for you if Theresa May wins with that landslide. It will mean you won't get any chance of holding onto your local hospital or protecting your local school. Having strong local Liberal Democrat MPs in places like Southport, Hazel Grove, and Gorton is your best chance of making sure we avert that crisis."

He added: "We have a fantastic candidate in Lisa Smart. She is very popular and has a huge reputation locally. People know Theresa May will be prime minister on June 9 so what you've got is the ability to make an intelligent vote to defend your community and to defend you and your family's future."