The British government has given itself just 12 hours to debate Brexit’s thorniest issues

Despite this, the government has given MPs in the House of Commons just 12 hours to respond to the 15 amendments before they vote whether to adopt or reject them—six hours today and another six hours tomorrow. The amendments, which could radically alter the course of Brexit, are as follows:

• Customs Union (amendment 1, 2): Prevent the repeal of the 1972 act that brought the UK into the EU unless the government lays out its plans to negotiate a continued customs union after Brexit. The amendment says the government would need to do this by October 31 2018.
• Environmental principles (amendment 3): Maintain the EU’s environmental principles in domestic law after Brexit.
• Enhanced scrutiny procedure (amendment 4): Ensure that UK laws replacing certain EU laws—particularly those on employment and equality rights, health and safety protections, and consumer and environmental standards—would be subject to enhanced security procedures.
• Charter of Fundamental Rights (amendment 5): Transfer the EU’s charter of fundamental rights into UK law.
• Scope of delegated powers (amendments 10, 43 and 45): Only give ministers the power to alter retained EU law where “necessary” instead of where they think it is “appropriate”.
• Meaningful vote (amendment 19): Guarantee parliament a meaningful final vote on the Brexit deal and gives the House of Commons to power to decide the next course of action if parliament rejects the deal.
• Parliamentary approval for negotiations (amendment 20): Parliament would need to give approval for negotiations on phase two before they begin.
• Child refugees (amendment 24): Government must negotiate to maintain the right of unaccompanied child refugees in one EU state to join relatives in another
• Northern Ireland (amendment 25): Requires there be no changes to the current border agreement between Northern Ireland and the republic of Ireland unless the two countries reach an agreement to do so.
• Continuing relationship with the EU (amendment 32): Brexit would not prevent the UK from replicating EU law and the UK would continue to participate in EU agencies after it leaves.
• Date and time of exit (amendment 37, 39, 125): No fixed exit date for leaving the EU. The date would be subject to parliamentary approval.
• European Economic Area (EEA) (amendment 51): Require the UK to stay in the European Economic Area.
• Challenge retained EU law (amendment 52): Removes the section of the bill that allowed ministers to use directives to decide when individuals can challenge the validity of retained EU law after Brexit.
• Compliance with EU principles (amendment 53): Allow legal challenges to UK law if it fails to comply with the general principles of EU law.
• Scrutiny (amendment 110): Make a committee scrutinize statutory instruments used to amend retained EU law.

British prime minister Theresa May will be severely tested in the next two days, given her narrow majority in parliament. There are plenty of people both within her party and the opposition keen to upend the Brexit process, her leadership, or both. Unsurprisingly, some have likened the significance of the debate to the dramatic “Norway debate” of May 1940, which ended up replacing Neville Chamberlain with Winston Churchill.

And it will all happen rather quickly, not long before the two-year anniversary of the Brexit vote.