Updated at 14:30
Theresa May has said she wants to go back to Brussels "with the clearest possible mandate" to secure a Brexit deal.
She was speaking after two key amendments have been chosen by the House of Commons speaker to be voted on tonight.
They are a motion by Conservative MP Graham Brady - which calls for the Irish backstop to be replaced with "alternative arrangements".
Another is for Labour MP Yvette Cooper's plan to delay Brexit by nine months if no deal's reached by 26th February.
They were among seven amendments chosen by John Bercow for tonight's vote, which follows the rejection of the withdrawal deal in the House of Commons earlier this month.
Opening this afternoon's debate, Mrs May said she wants to work towards a deal that she knows can pass in parliament.
She said: "That means sending the clearest possible message - not about what this House doesn't want, but what we do want."
The results of the votes on the amendments should give a clearer indication of Mrs May's next steps, with voting due to begin from around 7pm.
However, any attempt to reopen negotiations would need the approval of the EU itself.
Picture by: PA/PA Wire/PA Images
'Malthouse compromise'
EU officials have reportedly dismissed a new Westminster proposal aimed at ending the ongoing impasse over Brexit.
It comes after the DUP joined senior Tory Brexiteers and Remainers in voicing support for the plan.
The so-called ‘Malthouse Compromise’ would involve a redrafting of the Brexit Withdrawal Agreement and an extension of the transition period until 2021.
The plan would see UK Prime Minister Theresa May returning to Brussels to renegotiate the backstop.
She would be attempting to convince the EU to replace it with a free trade agreement alongside new technology – that does not yet exist – to prevent a hard border.
The plan includes provision for a managed no-deal exit if all else fails. This would see the UK honouring its EU commitments until 2021 at which time it would leave on WTO terms.
Those waking up to the exciting news that Conservative Party MPs have agreed among themselves on a Brexit deal are going to be awfully disappointed to learn that said plan is almost certainly a non-starter with the EU and has been widely debunked https://t.co/45cwnd0SHV
— David Henig (@DavidHenigUK) January 29, 2019
The Guardian reports this morning that the plan was greeted with “immediate scepticism” from EU officials – who have warned that it is unworkable and fails to offer any certainty on the Irish border.
News of the proposals broke just a day after the EUs deputy chief negotiator Sabine Weyand warned that the Brexit Withdrawal Agreement will not be re-negotiated.
She noted that the agreement was “very much shaped by the UK negotiators” and said British attempts to reshape it were “a bit like snatching defeat from the jaws of victory.”
She said the EU remains unanimous in its belief that any time-limit to the backstop would render it useless.
Sabine Weyand, deputy Chief EU negotiator on #Brexit couldn’t be clearer today; the EU is not going to reopen the WA. https://t.co/esekpW04AK
— Simon Coveney (@simoncoveney) January 28, 2019
"DUP has given its endorsement"
It comes after the ‘Malthouse’ plan was backed by the DUP leader Arlene Foster as well as a number of prominent Tory Brexiteers, including Boris Johnson and Jacob Rees Mogg.
In a statement, Ms Foster said: “The DUP has given its endorsement to the plan.”
“We believe it can unify a number of strands in the Brexit debate including the views of remainers and leavers.
“It also gives a feasible alternative to the backstop proposed by the European Union which would split the United Kingdom or keep the entire United Kingdom in the Customs Union and Single Market.
“Importantly, this proposal would also offer a route towards negotiating a future trade relationship between the United Kingdom and the European Union.”
She also claimed there was now “confusion and disarray” in Brussels and accused the Irish Government “panic stricken behaviour.”
Additional reporting by Stephen McNeice