JO Swinson is in her Westminster office sucking on lozenges to help save her voice after appearing in TV studio after TV studio and at party hustings across the country all in a bid to succeed Sir Vince Cable as the new face leading Britain’s expanding “liberal movement”.

According to party insiders, the Scot is a clear favourite to wear the LibDem crown and become the party’s first female leader; all at the age of 39. If Ms Swinson does not win her party’s contest in late July, hats will be consumed up and down the land. 

The MP for East Dunbartonshire knows this is a propitious time to take over given the party’s success in the May local elections in England and the European elections.

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Opinion polls continue to show the four main UK parties are evenly spread with the latest showing just three points between the Tories, Labour, Nigel Farage’s Brexit Party and the LibDems.

Two weeks ago, the former Labour, former Change UK MP Chuka Umunna defected to the LibDems. Ms Swinson says she is “encouraged” by the contacts she has been having and “continues to have” with MPs in other parties and hints that more defections could follow as talks are pursued across party lines. But she is not giving any names or numbers; just yet.

Unlike Peterborough, she is hoping parties like the Greens give the LibDems’ candidate, Jane Dodds, a clear run in the forthcoming by-election in Brecon and Radnor as her party is “best-placed to win” and everyone can see the “lie of the land”. “We need to be smart,” she declares.

While Ms Swinson might wish some collaboration in the forthcoming by-election, she seems clear there will be none with the Conservatives or Labour to form a government if there is another hung parliament following the next General Election. The stumbling block is, of course, Brexit.

The subject causes Ms Swinson to purse her lips, complaining it has turned British politics into “complete madness”. A second referendum, now her clear mission in life, is “without a shadow of a doubt the best way out of this absolute mess”.

But when it is put to her most people knew what they were voting for in June 2016 – the principle of leaving the EU, believing the details of departure would follow later – the deputy leader insists: “No, no, but it’s an irrevocable step. 

“I don’t have confidence and I don’t know how anyone can have confidence that it is the will of the people to go down any specific Brexit path. Do we really have confidence a majority of people want a no-deal Brexit? No. Do we really have confidence a majority of the public want Theresa May’s Brexit deal? No.” 

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Embarking on such an irrevocable step without majority support would be the “height of irresponsibility”, she insists.

The East Dunbartonshire MP believes Brexit has exposed a new faultline in British politics, which is now dominated not by a fight between Left and Right but between populism and liberalism.

Stressing how she regards both the Tories and Labour as being led by populist Brexiters and are “so much an anathema to our values,” Ms Swinson says she could not, as LibDem leader, ally her party to either of them in the current circumstances.

“I have not said never in any future scenario, where things are different. I’m looking at the situation right now in terms of being led by Brexiters on both sides. The same holds for confidence and supply. We need to stop Brexit and work with people who agree with us on that and that’s not the leadership of the Conservatives or the Labour Party.”

But it is suggested if Jeremy Corbyn were to heed the arguments of shadow Cabinet colleagues like Tom Watson and Keir Starmer and emulate the position of the Scottish Labour Party to swing behind a People’s Vote in all circumstances and campaign to Remain, this would hit the LibDems’ electoral appeal.

Ms Swinson said: “Hang on. I want to stop Brexit and I want as many people as possible to genuinely come on board. I’m afraid…[with] Jeremy Corbyn there is no other explanation than he is a Brexiteer. It doesn’t matter to him what his party members said to him at conference last year, whether the electorate sends him a very clear message through the local elections and European elections, or what his MSPs are saying to him; he is still saying, well, maybe we will have a chat about that at shadow Cabinet, maybe we should discuss this in September. Do you not realise Jeremy there is a deadline on October 31 looming and you are saying: ‘Maybe?’”

The deputy leader makes clear she does not believe the Labour leader will come round to supporting a Remain position in a second poll, saying he “chokes on saying the words People’s Vote”. 
“He hasn’t even been able to say how he would campaign and which way he would vote if there was another referendum or whether he would vote to stay or not. Look, this is a man, who wants to leave the EU. 

“It is such a tragedy for our country that at this point he is in charge of the Labour Party.”
Ms Swinson, a mother of two young children, says she wants to be Britain’s next prime minister to stop the two main parties taking Britain down a “really damaging path” and she does not have confidence she could leave the country’s future to their leaderships.

In particular, she says Brexiter Boris Johnson as PM would be a “disaster”, claiming he does “not care for anything beyond Boris Johnson” and is even “not fussed” about maintaining the Union.

She adds: “He can be beaten. We need to be more optimistic and positive about saying we are not just going to lie down and accept that future has to happen. I’m going to roll up my sleeves, I’m going to run for leader of my party, I’m going to build a liberal movement and take on these forces of nationalism and populism because Britain deserves better, Scotland deserves better.”