Six MPs have joined the Lib Dems in the past three months, bringing the party’s total in the Commons to 17.

Welcoming Smith, Lib Dem leader Jo tweeted: ‘She’s the sixth new MP to join us in the last three months, along with over 30,000 new members.

Together we can stop Brexit.’ The Sunday Times reports the Smith says both Labour and the Conservative Parties are ‘in the grips of extremists’.

In a blog post for the Lib Dems published on Saturday, Smith called for more inclusive and tolerant politics as well as fighting against Brexit. She wrote: ‘Our country deserves better than this. At a time of national crisis, people deserve a better choice than the two old parties.

‘I am therefore delighted to be joining Jo Swinson and the Liberal Democrats. ‘The Liberal Democrats are the strongest party to stop Brexit and build a society that gives opportunities to everyone, tackles the climate crisis and invests in our public.’

Swinson left a not very subtle clue that she might be welcoming a new member today, sharing the musical score for the Sound of Music classic ‘Sixteen Going on Seventeen’.

Smith joins former Change UK members Chuka Umunna and Luciana Berger in joining the party. Boris Johnson watched the Tories lose their parliamentary majority in real-time on Tuesday when Philip Lee walked across the chamber to sit with Swinson.

Deputy Liberal Democrat leader Ed Davey also greeted Smith to the party, tweeting: ‘We’re going to need a bigger bench.’ Smith found herself in hot water in February when she described black and minority ethnic people as ‘funny tinge’ on BBC Politics Live – just hours after quitting Labour.

She later apologised for the remark saying she misspoke because she was ‘very, very tired’.