The Liberal Democrats have been boosted by former Labour-turned-ChangeUK MP Chuka Umunna joining the party.
The former shadow business secretary quit Labour in February this year to join the new Independent group, which became Change UK ahead of the European elections last month.
Following disappointing election results, where Change UK failed to make major gains but the Lib Dems came second after the Brexit Party, Mr Umunna went independent.
Now the Streatham MP has announced he is delighted to join the Lib Dems.
Mr Umunna said the Liberal Democrats are “at the forefront” of “a progressive and internationalist movement” in British politics.
He said: “Labour and the Tories are committed to facilitating Brexit, and Brexit makes ending austerity virtually impossible.
“The Liberal Democrats are not – they were arguing for a People’s Vote and to remain in the EU from the very start.
“I am convinced the Liberal Democrats, as the spearhead of a broader progressive movement in civil society, offer the best chance to improve the lives of those I represent as well as countless other citizens across our country.”
Lib Dem leader Sir Vince Cable welcomed Mr Umunna into the fold.
He said: “Chuka and I have worked together effectively for many months, campaigning for a People’s Vote and to Stop Brexit.
“I know that he will be a great asset to our party not just on Brexit, but in fighting for the liberal and social democratic values that we share.
“He joins alongside 20,000 people across the country just this month, demonstrating clearly that the Liberal Democrats are the biggest, clearest and most formidable force in the liberal centre-ground of British politics today.”
As a Labour MP, Mr Umunna launched a leadership bid in the 2015 contest eventually won by Jeremy Corbyn, but withdrew three days later saying he was “uncomfortable” with the publicity.
He was widely expected to become the leader of Change UK, but ended up as party spokesman instead.
His decision to join the Lib Dems was welcomed by current deputy leader Jo Swinson, who is running for leadership of the party.
She said: “I have worked with Chuka on the People’s Vote campaign, and I know the passion, intellect, and energy he will bring to our party, and our campaign to stop Brexit.
“This proves that the Liberal Democrats are the rallying point for those who are opposed to Brexit, want to tackle the climate emergency and want to stand up to the forces of nationalism and populism.
“There are millions of people, like Chuka, who share those values, and I want them to join our party.”