Theresa May is heading for top-level talks in Berlin and Paris as she seeks European support to stop us crashing out of the EU on Friday.
The prime minister will meet German chancellor Angela Merkel and French president Emmanuel Macron ahead of a crunch EU summit on Wednesday.
All 27 remaining EU heads of government must agree to an extension if the UK is to avoid the default position of a no-deal Brexit at 11pm on Friday night.
EU officials are said to be considering delaying Brexit by a year.
Mrs May wants an extension until June 30 in order to come up with a plan alongside her Labour counterparts to get a deal through Parliament.
On Monday night, MPs and peers backed a new law to extend the Brexit process and cross-party talks will continue in the hope of finding a compromise.
The EU is likely to make a series of demands if it is to agree to a further extension of Article 50 – the legal mechanism through which Brexit is controlled.
According to reports, there are two possible proposals being considered by EU leaders.
The first is that Brexit will be delayed until May 22 if Mrs May manages to get a deal through the Commons by Friday.
This is looking unlikely as so far talks between Labour and the Conservatives are not producing anything concrete.
Labour want to be part of a customs union with the EU while Theresa May does not.
Labour leader Jeremy Corbyn says the Government needs to be more flexible regarding its red lines.
If an agreement can’t be reached, a second plan could come into play, which would see EU leaders consider a nine or 12-month extension.
That would take us through until December 31 2019 or March 31 2020 – meaning the UK has to take part in the next European parliamentary elections.
That is something that will appal Brexiteers within Mrs May’s party.
The reports also suggest that one condition for a lengthy extension would be that the UK cannot disrupt EU decision-making.
That could see it sidelined from budget decisions.
Arch-Brexiteer Jacob Rees-Mogg has previously said that if there is an extension and the UK remains in the EU then it should do everything it can be ‘be difficult’ until it leaves.
French leader Macron has been vocal about demanding something new in order to grant an EU extension.
However, he is unlikely to want no-deal because it would cause chaos at the port of Calais and he will not want to be responsible for problems with the Irish border.
Mrs Merkel has previously come to Mrs May’s aid and called on EU leaders to show more flexibility to the plight of the UK.
While Mrs May is in mainland Europe, her defacto deputy David Lidington will hold talks with Labour’s shadow Brexit secretary Sir Keir Starmer.