- Watch: Heidi Allen takes her seat in the Commons as a Liberal Democrat
Heidi Allen, who represents South Cambridgeshire, has become the latest MP to join the Liberal Democrats.
Ms Allen has been an independent since June when she quit Change UK, who she joined from the Conservative Party four months earlier.
She is a remain supporter, and said the Lib Dem's ambition to stop Brexit was one of her main reasons for joining.
The 44-year-old said: "Now is the time to stand shoulder to shoulder with, not just alongside, those I have collaborated and found shared values with.
"Shifting to the extremes, the Conservatives and Labour have turned their backs on the liberal, progressive centre ground our country is crying out for.
"As we face the monumental task ahead of stopping a damaging Brexit, healing the rifts in society and rebuilding the UK, there is only one party with the honesty, energy and vision to do that - and that is the Liberal Democrats."
Ms Allen, who held the post of interim leader at Change UK, is the latest high profile MP to join the Liberal Democrat ranks.
She has announced that she will represent the party in her current constituency of South Cambridgeshire at any upcoming election.
The seat has traditionally been a Conservative stronghold; Ms Allen held it with a majority of 16,000 in the 2017 general election.
Her switch means the Lib Dem's existing Parliamentary Candidate, Councillor Ian Sollom, has had to step aside.
He reacted to the news on Twitter:
The Lib Dem ranks have swollen in the past months, and they now have 19 MPs.
Ms Allen's move follows the recent arrivals of ex-Tories Sarah Wollaston, Sam Gyimah and Phillip Lee as well as former Labour MPs Chuka Umunna, Angela Smith and Luciana Berger.
Party leader Jo Swinson said: "She has long been an ally in the fight to stop Brexit, and having worked with her I know the energy and passion she will bring to our party.
"This once again proves that the Liberal Democrats are the strongest party of remain."