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.
Yesterday a minister unexpectedly resigned over the government's Brexit strategy, but one of his constituents is still absolutely fuming about it.
He said that remaining in the EEA, which includes membership of the single market, was not a flawless solution.
Caroline Flint, a remainer whose Don Valley constituency voted more than two to one to leave, defended her constituents who she said had been insulted "day in and day out by some of the comments in this place and outside are not against all migration".
The Prime Minister appeared to have defused a potentially explosive row over the EU customs union on Monday night as Tory pro-Europe rebels Sir Oliver Letwin and Nicky Morgan and Brexiteers Jacob Rees-Mogg and Sir Bill Cash came together to table a separate compromise amendment backing "a customs arrangement" with the EU.
"She said that anything which undermines the government at home would make the negotiations with the European Union more hard".
Eurosceptics urged the government to hold firm, saying the rebels were seeking to undermine the 2016 referendum vote for Brexit.
But Britain - and its government - remain divided over Brexit, and European Union leaders are frustrated with what they see as a lack of firm proposals from the U.K about future relations.
After it was not clear whether that would win over potential rebels, a minister offered Grieve a compromise to discuss parts of his amendment that the government could adopt - a move aimed at warding off a potential rebellion led by the lawmaker. The government earlier had said it would not support that amendment.
The pro-European cause was boosted when junior justice minister Phillip Lee, a friend of May's, resigned shortly before the debate in order to back the veto amendment. The government is trying to reverse changes inserted by the House of Lords that would soften the terms of Brexit and give Parliament more say in the process.
"We must under all circumstances respect the result of the referendum", Brexit Secretary David Davis told lawmakers as he opened the debate.
Talks with Brussels have stalled over the fraught issue of the Irish border, but both sides are hoping to agree a deal by October in time for the Brexit date of March 29, 2019.
But that vote required last-minute concessions to pro-European Tories, and they warned Wednesday they could yet seek to defeat the government if May fails to fulfil her promises.
But he insisted Labour could not support the so-called Norway model as he did not believe it was the "right option" for the UK.
Shadow Brexit Secretary Keir Starmer commented: "This vote was about ensuring parliament was given a proper role in the Brexit negotiations and that we avoid a no deal situation, which is becoming more likely with the divisions at the heart of this government".
"The question of what form parliamentary approval of the withdrawal bill takes is one of the most significant decisions this house will have to take", he said.