The government's victory in last night's EU Withdrawal Bill vote was superficially comfortable. The Brexiteers won the vote by 326-290, with seven Labour MPs (Ronnie Campbell, Frank Field, Kate Hoey, Kelvin Hopkins, John Mann, Dennis Skinner and Graham Stringer) backing the bill and six abstaining. Only one Conservative MP (Ken Clarke) aided the Remainers by abstaining.

But as Stephen wrote this morning, life now gets harder for Theresa May. Within minutes of the bill's passage after midnight, MPs were queuing up to table amendments. Tory Remainers have long regarded the bill's committee stage as their moment.

A total of 136 amendments and 29 clauses have been tabled by MPs. This includes 24 by the Labour leadership, but even May's most ardent opponents are unlikely to back anything with Jeremy Corbyn's name on it. For this reason, the amendments to watch are those tabled by Labour and Tory backbenchers.

Nine Conservative rebels (including Ken Clarke, Dominic Grieve, Nicky Morgan and Anna Soubry) have demanded that the government "empower Parliament to control the length and basic terms of transitional arrangements". At present, though May has accepted the need for a transitional period after Brexit (or "implementation period" as she prefers to call it), she has ruled out continued membership of the single market and the customs union. But Labour's changed stance creates a potential parliamentary majority for a softer transition. A Tory amendment explicitly calls for the UK to "retain the provisions of the European Economic Area Act 1993 as part of domestic legislation beyond exit day" (in effect, guaranteeing continued single market membership).

The same nine Tory rebels have also called for the government to ensure that the final Brexit deal is "approved by statute passed by parliament" (as May has promised) and for ministers to "remove the exclusion of the Charter of Fundamental Rights from retained EU law" (the charter guarantees a panoply of human rights). Twelve Conservative MPs have backed a reduction in the so-called "Henry VIII powers", which would allow ministers to make sweeping changes to UK law without parliamentary approval.

Though it was the public who voted for Brexit (the first time a referendum had not affirmed the status quo), it is MPs who will determine the form it takes. For decades, it was Eurosceptics who revered parliamentary sovereignty. But as Remainers seek a softer Brexit, and as Leavers seek an unimpeded withdrawal, their roles have now been reversed.