"We campaigned for remain but many of our MPs, including myself, now represent seats which voted heavily leave".
MPs, ministers and officials all agreed Tuesday that a soft Brexit or even the prospect of no Brexit is greatly increased - so too the prospect of a snap early election before the end of the year.
Yet this week's marathon Brexit debate have Labour members of Parliament concerned about their Brexit-voting electorates - and pro-European lawmakers frustrated by Corbyn's euroskeptic history - airing frustrations in full view.
The lower chamber, the House of Commons, voted against amendments introduced by the House of Lords.
A Tory Remain rebel has warned Theresa May that "if she f**ks us, she's f**ked, ' after Conservative MPs were given assurances by the prime minister that a compromise Brexit amendment to the 'meaningful vote" will be upheld.
With not all rebels persuaded that May's plan can prevent an economic shock after Brexit, some say they will challenge her plans to leave the customs union again during votes on other bills, on trade and customs, which will be brought back to the house some time before July 24. This was defeated by 322 votes to 240.
Brexit is due in nine months and an exit agreement probably has to be made by November in time to be ratified by 27 European Union parliaments.
But, the pro-EU MPs' version of what they were promised appears to differ from what they government says it offered, threatening to reignite the dispute and reviving the possibility of a revolt that would badly damage May's authority.
In response to the votes, Lib Dem leader Sir Vince Cable accused Labour of conspiring with the Conservatives to "wave through a hard Brexit".
Parliament voted 325 to 298 in favor of rejecting a House of Lords amendment to require ministers to report on their efforts in negotiations to secure a customs union.More news: E3 2018: Star Fox and Starlink Crossover Announced at Ubisoft E3 Event
Supporters of this policy argue it would protect British jobs and go some way to preserving the invisible Irish border, while detractors point out it would prevent Britain from signing its own trade deals after it has left the EU.
The rebels are seeking both closer ties with the European Union on issues like trade and customs, and to ensure that the government does not follow through on its threat to leave the bloc without a deal if it does not like the terms on offer from Brussels. The UK is committed to no customs posts between Northern Ireland and Ireland and has come up with two suggestions (Max Fac and a customs arrangement) to allow this. This is where Conservative rebels like Nicky Morgan, Anna Soubry and Ken Clark are expected to make their biggest move on customs.
But this Bracknell Brexit-backing constituent really was not happy.
Labour shadow minister Laura Smith and four other opposition MPs have resigned from party roles, over a whip forbidding them from voting in favour of the Lords amendment to keep the United Kingdom in the European Economic Area (EEA).
Corbyn instructed his MPs to abstain on the amendment, meaning they should neither vote for or against it.
At the Hay Festival 10 days ago, the former Labour foreign secretary David Miliband said Mr Corbyn "should not be the midwife for a hard Brexit".
Laura Smith resigned from her junior shadow cabinet role in the run-up to the vote.
Ged Killen, Ellie Reeves, Tonia Antoniazzi, Rosie Duffield and Anna McMorrin all handed in their resignations as parliamentary private secretaries (PPPs), alongside Smith.
There was little doubt the government would win on the customs union and single market, which some pro-EU lawmakers say is the only way for Britain to retain economically advantageous close ties with the bloc, with the opposition Labour Party also divided over future relations.
The 15 Labour EEA opponents included Frank Field, Caroline Flint and Dennis Skinner.