Tactical voting and disaffection with mainstream parties make this Thursday a once-in-a-lifetime general election that could reshape the political landscape for decades, the leader of the Liberal Democrats has argued. With a series of smaller parties expected to make breakthroughs in terms of vote share and seats, Ed Davey said the Lib Dems seemed poised to entrench themselves in a swathe of formerly Conservative territory, particularly in the south. “I think this is a once-in-a-century election,” the Lib Dem leader told the Guardian between campaign stops in Tory-held seats. “I mean, 1997 was a once-in-a-generation. This is a once-in-a-century.” Launching the final week of his defiantly unorthodox campaign with a bungee jump at a football ground in Eastbourne followed by a Zumba class in John Redwood’s former seat of Wokingham, Davey insisted such antics had brought attention to party policies in areas such as social care and sewage in rivers. “We’ve never seen Liberal Democrat policies talked about as much,” Davey said, speaking in a rear section of the party’s battlebus festooned with wetsuit tops and swimming shorts drying on the backs of the seats. “Isn’t that weird? When we’ve done it from a lectern in a suit at a press conference, people don’t want to talk about our policies. When I fall off a paddleboard or go down a waterslide, people talk about our policies. I like to think we are running a positive campaign, a bit of fun but mixed with serious messages. “After I did the bungee jump, one of the guys who works at the football club stopped me, saying that he looks after his dad and what we’re saying about care and carers is so important.” While the Lib Dems are at pains not to formally reveal how many target seats they are focusing on, an initial focus of about 50 has expanded as formerly unwinnable constituencies including Stratford-on-Avon and South Cotswolds have come into play. Dislike of the Conservatives and an increased willingness for people to vote tactically to remove Tory MPs could have a particular impact in such areas, Davey said. “We will take out a lot of Conservatives,” he said, arguing that formerly ultra-safe Tory areas such as Henley, once represented by Boris Johnson, and Witney, David Cameron’s former seat, were on “a knife-edge” and Sussex was “looking incredible”. “People are realising that this is a quite extraordinary election. They need to vote tactically to get out the Conservatives. In many cases, that’s us,” he said. “People should recognise that this is an election where you can literally change the political geography of our country, and for a long time. Be brave, do something different.” While the same polls that have said the Lib Dems could end up with 60 or more seats have also predicted gains for the Greens and Reform UK, Davey said it could be harder for these parties, given the need for resources and, apart from in a few places for the Greens, a base of local councillors on which to build. In the 2019 election, Davey said, the Lib Dems “started fighting places where we hadn’t got councillors”, piling up more votes but producing just 11 MPs, an experience that directly led to the current ultra-focused campaign. Some polls have said the Lib Dems could even end up with more MPs than the Conservatives, becoming the main opposition. Davey, however, said the only target was to overtake the Scottish National party and become the third biggest party in the Commons. “What I can say is our campaign is [going] better than we had expected,” he said. “I’m going to seats that I hadn’t expected to. But I’m cautious as well, because we don’t want to overstretch ourselves. “The Tories have helped us because they have been so awful. I’m happy to concede that. The desire to remove this shockingly bad government has focused people’s minds and they have looked beyond the tribal lines in a way which I haven’t seen before. “There is a chance that people will vote for the party best placed to beat the Conservatives, and people know in the south of England and the south-west that’s us, broadly speaking.” Much of the campaign success so far has hinged on Davey’s willingness to throw himself into a variety of camera-friendly stunts. He began Monday morning bungee jumping from a platform hoisted by a vast crane at Eastbourne’s football club, yelling “Vote Liberal Democrat!” as he fell. Hours later, wearing an orange-pink T-shirt and black shorts, Davey was enthusiastically joining in with a Zumba class in a Wokingham park, carrying on for several songs, by which point most of the photographers had stopped taking pictures. While large parts of Thursday’s outcome remain in doubt, Davey said he was certain of one thing. Asked if this was the most fun he had had in an election campaign, he replied immediately: “Yes. Without a doubt.”