Jo Swinson toughens stance on propping up Labour or Tories, saying leadership change would not be enough

Liberal Democrat leader says main parties would be 'in the clutches' of political extremists even if they ditched Boris Johnson and Jeremy Corbyn

Jo Swinson has hinted that she would not be willing to help the Conservatives or Labour to form a government even if they changed their leaders, as she toughened her stance on propping up either of the main parties in the event of a hung parliament.

The Liberal Democrat leader claimed both parties had "headed off to the extremes" and would remain "in the clutches" of people on the hard left or the hard right even if they ditched Boris Johnson and Jeremy Corbyn.

The comments follow speculation over whether Ms Swinson would help either of the main party leaders to become prime minister in the event of the 12 December election delivering another hung parliament.

Launching her party's campaign on Tuesday, she "absolutely categorically" said she would not help to put Jeremy Corbyn in No10 even if he promised to deliver a fresh Brexit referendum.

Speaking to The Independent during a campaign visit to Golders Green, north London, on Wednesday, Ms Swinson also ruled out supporting Mr Johnson.

She said: "I will be categoric about both of those men: neither of them are fit to be the prime minister. Liberal Democrat votes will not be supporting either of those men to be prime minister."

Ms Swinson suggested that even a leadership change by the main parties would not be enough to secure the Liberal Democrats' support and said a more fundamental change would be needed.

She said: "Those individuals are not fit to do that job, not up to the job of prime minister, but it's also fair to say that in both cases those individuals represent the way in which those parties have vacated their previous grounds.

"You have a Conservative Party that is essentially aping the Brexit Party and that type of populism, [and] you have a Labour Party that has gone off to the hard left and that type of populism.

"I think it's very likely that if either of those were to be replaced, you would still find those parties in the clutches of either those on the hard left and those on the hard right, and as Liberal Democrats we want to a see a liberal, inclusive society."

She added: "There are many people who share our liberal values who are not yet in the Liberal Democrats - that includes some people in those parties but it typically doesn't include people on the hard left or on the hard right."

Ms Swinson was welcomed to Finchley and Golders Green by Luciana Berger, the former Labour MP who is now standing for the Liberal Democrats in the constituency.

The pair met leaders of Jewish mental health charity Jami, which runs a cafe designed to help people struggling with mental health problems.

The constituency has traditionally been a Labour-Conservative marginal but early polling suggests Ms Berger could be on course for a shock victory, amid anger over the Tories' Brexit stance and Labour's failure to tackle antisemitism in its ranks.