Three Labour frontbenchers quit their posts today as Keir Starmer was hit by a Brexit revolt.
The party leader ordered his MPs to vote with the Government and approve Boris Johnson’s trade pact with Brussels.
But 37 staged a rebellion, including three shadow ministers or parliamentary aides.
A total of 36 abstained – defying a three-line whip to back the pact.
Only one, Bell Ribeiro-Addy, the MP for Streatham, South London, voted against.
Moments after the result of the vote was declared, frontbencher Helen Hayes announced she had quit her role.
She tweeted: “I’m grateful to all who’ve contacted me on the EU Future Relationship Bill.
“I can’t vote for this damaging deal & have abstained today.
“With much sadness & regret I’ve offered my resignation as Shadow Cabinet Office Minister. It’s been a privilege to serve.”
MP for Gower, South Wales, Tonia Antoniazzi said it was “with the deepest regret” she was resigning as a parliamentary aide to the Shadow Scotland and Work and Pensions teams.
“I cannot in good conscience vote for (the) European Union (Future Relationship) Bill which will make this country poorer, affect people’s ability to work and live in the EU and hamper our ability to trade with the word’s largest single market and our closest neighbours,” she told Mr Starmer.
Branding the Bill “a step backwards for our country”, she added: “The deal is not good enough for Britain, not good enough for Gower and not good enough for me to vote for.”
Florence Eshalomi, MP for Vauxhall, South London, quit as a whip – a frontbencher responsible for enforcing the leader’s power.
She said: “This Bill was rushed and a ‘no deal’ is the worst outcome for the country but I cannot support the bill and I have abstained.
“I have offered my resignation as an Opposition Whip.”
The resignations are a blow for Mr Starmer’s bid to reposition the party.
He ordered Labour MPs to back the agreement, believing Labour needed to show voters in its traditional heartlands – most of which overwhelmingly backed Leave in the 2016 referendum – that it has heeded the result.
Urging MPs to back the deal, Mr Starmer told the Commons: “This is a simple vote with a simple choice – do we leave the transition period with the treaty negotiated with the EU or do we leave with no deal?
“Labour will vote to implement this treaty today to avoid no-deal and to put in place a floor from which we can build a strong future relationship with the EU.”
But former Shadow Home Secretary Diane Abbott, MP for Remain-supporting Hackney North in London, abstained on the “shoddy” pact.
She told the Commons: “By driving this historic deal through Parliament in one day with no time for proper scrutiny, this Government is trashing democracy.”
The agreement “falls short in many policy areas”, including security, said Miss Abbott.
She added: “I have the greatest respect for the result of the 2016 referendum, but this shoddy deal falls short.
“It fails the British people, it fails my constituents and I have to meet my responsibilities as a member of the British Parliament and vote against it today.”
Fellow rebel and former Shadow Defence Secretary Clive Lewis, MP for Remain-backing Norwich South, claimed Brexit “has shone a light on the deep democratic deficits in our arcane political system”.
He said: “Change was demanded, more control was promised and yet what we are presented with today is ironically more of the same – unaccountability, power concentrated in the hands of a few, an over-centralised Government evading scrutiny to act in favour of vested interests and impose decisions from the top down.
“I will play no part in giving this Government a blank cheque to bulldoze through democratic oversight and I will not be voting in support of this legislation.”
Meg Hillier, who chairs the Public Accounts Committee and represents Hackney South and Shoreditch, abstained.
“This lack of scrutiny and the impossibility to read this Bill properly makes me unable to support it today,” she said.
“I’m not voting against because I recognise the vote in 2016 and 2019 give this Government licence to take us out of Europe.
“But I can’t be complicit in what is a wrecking ball in the name of sovereignty.
“But I do say we now need to drop the Remainer and Leaver labels.”