Critics said the amendments to the Customs Bill laid down by Eurosceptics on Monday would undermine the UK's recently-announced negotiating position.
The prime minister avoided all-out Tory civil war and the wrath of the Eurosceptic wing of the party less than 24 hours after she capitulated to concessions that they believed had killed off her Chequers plan.
We have been in contact with United Kingdom civil servants working on Brexit policy, who have confirmed that the White Paper's proposals in respect of financial and professional services are a pragmatic response to the basic premise that as the United Kingdom will no longer be members of the Single Market, we will inevitably enjoy less market access than we do now.
Theresa May's former Education Secretary Justine Greening earlier demanded that United Kingdom citizens be given the choice to remain in the European Union in a second Referendum.
One of the amendments practically says that the United Kingdom should not be collecting tariffs for Brussels unless the European Union does the same for Britain, one of the key ideas in May's original Brexit white paper that was created to keep the Irish border invisible.
It has emerged that No. 10 has proposed bringing the summer recess forward to Thursday to limit the time available for Conservative MPs to hold a confidence vote in her leadership.
However, she has told unhappy lawmakers that they needed to back her or risk there being no Brexit at all.
That, in turn, will prove the PM with a clear sense of how many MPs would be willing to vote against a final Brexit agreement this Autumn - so it's a big deal.
May had to fight hard to get the agreement of Cabinet ministers at her Chequers country residence earlier this month for her vision for Britain's future ties with the EU. Or, thirdly, to stay remaining in the EU.
However, Labour is understood to have instructed its MPs to vote against the move and several pro-European Tories have already indicated they will oppose any attempt to cut short the term with so much work to do on Brexit. Earlier Monday a parliamentary private secretary quit her team.
On Monday, May gave in to Tory hardliners by accepting four amendments to the bill, underpinned by her Brexit white paper, meant to toughen up her negotiating stance.
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