The Prime Minister is facing a difficult day on all fronts, with rebel Remainers and Leavers both plotting to publicly go against her, just days before the start of summer recess.
Theresa May was faced with yet another Chequers-prompted resignation yesterday, after ministerial aide Robert Courts quit, tweeting that he wanted to "express discontent with #Chequers in votes tomorrow".
The MP for Witney and West Oxon – David Cameron's successor – added: "I had to think who I wanted to see in the mirror for the rest of my life. I cannot tell the people of WOxon that I support the proposals in their current form".
Frontbenchers including international development secretary Penny Mourdant, work and pensions secretary Esther McVey and Brexit minister Suella Braverman are still under the spotlight as potential bolters.
However May's position looks safe for now, with Brexiter MPs telling City A.M. they fear she would survive any vote of no confidence at this stage, which means she could not be challenged again for a year – well over the March exit date – leaving the Prime Minister free rein to get the Brexit terms she wants.
But even if they stay on, Courts will not be the only backbencher to speak out against the current direction of travel.
Former Brexit secretary David Davis is expected to give his resignation speech this afternoon, which is likely to cover the same ground his interviews have done so far – namely that the proposals could leave the UK outside of the EU but still beholden to its rules.
Another rebel Eurosceptic adding to May's headaches is Jacob Rees-Mogg, who has tabled four amendments to the so-called customs bill. Although it is not expected that the pro-Brexit MPs, led by the European Research Group, will defeat the government on any critical issue it could prove damaging to the Prime Minister and pave the way for further upset at the third reading stage.
The same piece of legislation, formally known as the Taxation (Cross-Border) Bill, is also expected to face a tough time from Remainers, who have signed an amendment of their own, urging the government to seek a form of customs union after Brexit as part of the negotiations. Although Remainers have so far failed to present a firm front, they have warned that previous battles over the EU Withdrawal Bill were merely a warm up for this week.
Remainers are increasingly speaking out. Former Cabinet minister Justine Greening this morning went public with calls for a second referendum, arguing the only way out of the "deadlocked" position is to "give [the decision] back to the people."