Victory for Boris Johnson in the Tory leadership race could be a “great recruiting tool” for the Liberal Democrats, Jo Swinson has said.
The Lib Dem leadership hopeful said Mr Johnson would be “disastrous for our country” but “the silver lining is it’s good for the Liberal Democrats”.
Meanwhile, her Lib Dem leadership rival Sir Ed Davey suggested that a government of national unity led by a Labour backbencher could be a way of stopping a prime minister intent on a no-deal Brexit.
The Lib Dems have enjoyed a poll surge at the local and European elections in response to their anti-Brexit stance.
A Johnson premiership committed to Brexit on October 31 with or without a deal could boost the Lib Dems further, Ms Swinson suggested.
She also said talks were taking place with Tory MPs about potential defections after former Labour and Change UK MP Chuka Umunna joined them.
Speaking to journalists at Westminster she said: “I have and will continue to have private conversations.
“I’m keen to grow the Liberal Democrat parliamentary party in a variety of ways.”
Conversations had taken place “pretty recently, within the last week or two”.
She tore into Mr Johnson about his “careless” use of language.
Asked if she thought Mr Johnson – who has compared veiled Muslim women to “letter boxes” and referred to black people as “piccaninnies” – was racist, she said: “I don’t know, because I don’t know what he thinks.”
She added: “It’s not acceptable for somebody in his position to be so careless with the use of language where we have a society where people are, day in day out, abused and subject to discrimination because of the colour of their skin.”
In relation to Mr Johnson’s domestic row with girlfriend Carrie Symonds, she said: “Whatever happened at the weekend, regardless of that, we already know Boris Johnson isn’t fit to be prime minister.
“We already have plenty of things that he has done in his public life that show that he is absolutely not a statesman.”
Former Cabinet minister Sir Ed also floated the possibility of further defections to the Lib Dems.
Asked if former Tories Heidi Allen and Sarah Wollaston – who like Mr Umunna left Change UK in early June – would be joining, he said: “I don’t know. I have talked to Heidi, I haven’t actually talked to Sarah.
“I would be very happy for them to join. I think, having listened to them and heard their position on Europe and other issues they would fit well in our party.
“We need to become a political home to pro-EU liberal Tories and pro-EU liberal and social democrat Labour MPs and voters.”
Setting out his proposal for a government of national unity, he said it would be formed if there was a vote of no confidence in the administration led by the new prime minister.
By setting up an alternative to Jeremy Corbyn entering Number 10, Sir Ed suggested it might help secure the support of 25-30 Tory MPs for the confidence motion.
He suggested a respected backbencher such as Yvette Cooper or Hilary Benn could lead the government, which would only exist for around six months to legislate for and deliver a new referendum on EU membership.
Sir Ed acknowledged: “I’m not suggesting everyone is jumping to this idea yet, it will take some persuasion.”
He said the leader “probably has to be a Labour MP because most of the MPs supporting this government of national unity would be Labour, so ultimately it’s a challenge to my Labour colleagues, many of whom understand Brexit, and the no-deal Brexit that threatens us, would be deeply damaging to their constituents.”