Chuka Umunna has denied his decision to defect to the Lib Dems was made out of “crude self interest”.
Speaking to Lib Dem members at the party’s conference in Bournemouth on Monday morning, the former Labour MP said joining the party was “one of the best political decisions I have ever made”.
Umunna, currently the MP for Streatham, intends to stand in the Tory held seat of Cities of London and Westminster at the next election.
“I’ve been to a few parties,” Umunna, who also helped set up but then left Change UK, said to laughter.
“From the bottom of my heart for making me feel so welcome. I could not be more at home in this Lib Dem family.
“The decision to join was not made out of crude self interest. If self interest or climbing the greasy pole is your goal, I would not recommend following my example this year.”
It came as former Labour MP Luciana Berger, who also defected to the Lib Dems, said she “looks forward to more colleagues” crossing the Commons to join the party.
She told a meeting on the fringes of the conference today that other MPs are being “held hostage” in their parties and many “have a glint in their eye” suggesting they could defect.
Umunna used his speech to launch an outspoken attack on the Labour Party and Jeremy Corbyn.
“You cannot be a champion of liberalism if you are currently subject to a formal Equalities and Human Rights Commission investigation for institutional racism against Jewish people,” he said.
“You cannot be a champion of liberalism when your leader’s supporters think it’s is acceptable to abuse, vilify and deselect anyone who dares question the leader.
“And you cannot claim to be liberal when the political editor of the BBC needs to take a body guard to your conference.”
Umunna, who is now Lib Dem foreign affairs spokesperson, also accused Corbyn of being an “apologist” for Russian president Vladimir Putin.
Lib Dem members yesterday overwhelmingly formally approved the party’s new policy to revoke Article 50 and stop Brexit should it unexpectedly win the next election.
Party leader Jo Swinson told her conference: “The Liberal Democrats are crystal clear: if we win the next election, we will stop Brexit.”
Swinson said this morning she was talks with other parties about standing aside in certain seats at the next general election to ensure that pro-Remain candidates are elected.
However, she ruled out the prospect of the party standing down for Labour candidates.
Speaking on BBC Radio Scotland’s Good Morning Scotland programme, she said: “They (Labour) want to deliver a Labour Brexit, they’ve been very clear about that, they’ve said they’re not a remain party.
“I’m a Liberal Democrat, I’m about stopping Brexit, I’m about keeping our place in the European Union, so I want to make sure that people have the choice to vote for a remain candidate who will stop Brexit and therefore, standing down for Labour doesn’t achieve that.
Swinson has been boosted by a series of defections to her party, including Umunna, since she became leader.