MPs are set for another vote on Brexit tomorrow, but it’s not quite the make or break moment some are spinning it as.
In simple terms, MPs will vote to say whether the Prime Minister came to the Commons within three Parliamentary days of her historic defeat on the Withdrawal Agreement to set out her plan B - which she did.
Tuesday's vote is not an endorsement of that plan, just an acknowledgement that she told MPs about it.
What are more important are a series of amendments tabled to the motion.
The majority of these amendments have no legal power, but if any of them receive the backing of MPs it would send a clear signal to the Government on what changes the Commons would want to see to the Withdrawal Agreement.
Replacing the backstop
The one which appears to favoured by the government has been tabled by Conservative MP Sir Graham Brady.
This is aimed at neutralising the controversial 'backstop' plan contained in the Withdrawal Agreement which prevents a hard border between Northern Ireland and the Republic. The backstop would see the UK follow the rules of the EU's customs union after Brexit until a trade deal has been agreed. MPs are unhappy with this plan as the UK would be unable to leave the backstop arrangement unilaterally, and there is no time-limit on how long it would last.
Sir Graham's amendment requires the backstop to be replaced with “alternative arrangements” in order to prevent a hard border with Ireland. Sir Graham believes if this passed it would strengthen May’s hand in her negotiations with the EU.
“If my amendment is carried, she goes back to Brussels and says: you wanted to know what we can get through the House of Commons? This is it,” Sir Graham said on Monday.
Not all MPs back the plan. Some hardline Brexiters think adding a “codicil” to the Withdrawal Agreement is not good enough, as the backstop still remains. Anti-Brexit MPs believe the EU will not agree to the proposal, and pushing ahead with it simply wastes time that could be spent striking a different deal.
The other amendment which could drastically alter Brexit has been tabled by Labour MP Yvette Cooper. Her plan would see MPs seize control of Parliament timetabling from the government, allowing a a vote on legislation that would force May to delay Brexit if a deal with the EU cannot be agreed.
That amendment has stiff opposition among Brexiters, but some high profile Tories - including work and pensions secretary Amber Rudd - are keen to back it.
It is not yet clear whether Labour leader Jeremy Corbyn will support the plan, and it is believed he would want to limit any delay to three months, instead of the proposed nine.
Whether MPs vote on these amendments comes down to one man - Commons Speaker John Bercow. He will decide on Tuesday morning which ones will be put before the House, and voting will begin at around 7pm.