Brexit: John Bercow says there is 'arguable case' government has committed contempt by failing to publish legal advice

Attorney General Geoffrey Cox: 'There is no unilateral right for either party to terminate Irish backstop if activated after the Brexit transition period'

Theresa May is facing a constitutional crisis after six opposition parties joined forces to accuse the government of contempt of Parliament over its failure to publish its full Brexit legal advice.

The Commons Speaker, John Bercow, said there was "an arguable case" that the government had committed contempt, after he was asked by Labour, the SNP, the Liberal Democrats, Plaid Cymru, the Green Party and the DUP to begin proceedings.

Earlier, Attorney general Geoffrey Cox admitted the UK could be locked into a customs backstop under the prime minister’s Brexit blueprint.

Mr Cox confirmed that neither the UK nor EU would be able to unilaterally end the Northern Irish backstop arrangement if it came into force, in an address to MPs.

It also comes as The Independent’s petition calling for a Final Say referendum on Brexit was delivered to Downing Street, after more than a million people backed the campaign.

See below for live updates:

Key Points

• 'I will still have my job after MPs vote on Brexit deal', says prime minister
• Campaigners deliver Final Say petition with 1.5m signatures to Downing Street
• PM's Brexit adviser says backstop is 'slightly uncomfortable necessity'
• Opposition parties write joint letter calling for government to be held in contempt
• 'Arguable case' that government committed contempt, says Speaker
• Theresa May told 'no legal guarantee' UK could withdraw from backstop

[3 December 2018 08:27 · Peter Stubley]

Good morning and welcome to The Independent's politics liveblog as the we prepare to deliver the petition calling for a final say on the Brexit deal.

[3 December 2018 08:35 · Peter Stubley]

Editor Christian Broughton will be delivering one million Final Say signatures and People’s Vote spokesman Chuka Umunna MP will be delivering 300,000 People’s Vote signatures to Downing Street at midday.

Campaigners will be gathering outside the Churchill War Rooms from 11am before setting off for the prime minister's residence at 11.30am.

[3 December 2018 08:55 · Peter Stubley]

Lib Dem leader Sir Vince Cable, former Green Party leader Caroline Lucas and former education minister Justine Greening are also due to take part.

The campaign has been backed by former PM Tony Blair, former Conservative attorney general Dominic Grieve, campaigner Gina Miller and ex-Labour spin doctor Alastair Campbell.

[3 December 2018 09:01 · Peter Stubley]

Sam Gyimah MP also urged Theresa May not to rule out calls for a Final Say referendum after resigning from his cabinet post as universities minister.

[3 December 2018 09:26 · Peter Stubley]

Later today attorney general Geoffrey Cox is due to make a statement in parliament about his legal advice on the EU withdrawal agreement.

Theresa May is facing calls to make the opinion public. Labour said it is ready to combine with other opposition parties to start proceedings for contempt of parliament unless the report is published in full. Boris Johnson has described the prime minister's refusal to do so a "scandal".

[3 December 2018 09:33 · Peter Stubley]

Theresa May's top Brexit adviser has privately warned her that a key element of her exit blueprint would be a "bad outcome" for the UK.

Oliver Robbins, who led the behind-the-scenes talks with Brussels, reportedly told the prime minister that there was no legal guarantee that Britain could withdraw from the "backstop", which aims to prevent a hard border in Ireland if future trade talks fail.

[3 December 2018 09:40 · Peter Stubley]

Businessman Sir Ian Wood has said Theresa May's Brexit deal is "workable" and is better than the current situation with Europe.

He told BBC Good Morning Scotland that the UK cannot afford to leave without a deal and that the plan now needs to "move ahead."

"There is not a solution which anyone, or I suspect even more than 50% of people, would really say 'that's a really good solution,'" he added.

Sir Ian, who made his fortune in the North Sea oil industry, also claimed that Brexit "will see significantly more fish coming to the Scottish fishing fleet."

[3 December 2018 09:50 · Peter Stubley]

Home secretary Sajid Javid has said that MPs are "very unlikely" to see plans for the UK's future immigration system before they vote on the Brexit deal.

Explaining the delay, the Home Secretary told BBC Radio 4's Today programme: "This is the biggest change in our immigration system in over four decades - the most significant change we're going to see in immigration as we take control of our immigration system, so it's important that we work on the details, that we listen to people, to businesses and others and we get the details right."

Mr Javid and chancellor Philip Hammond are reported to be pressing for the government to abandon the target of reducing net migration below 100,000 a year.

[3 December 2018 09:55 · Peter Stubley]

Brexit uncertainty contributed to the "lacklustre" performance of the UK manufacturing industry in November, according to the latest survey of the sector.

[3 December 2018 09:58 · Peter Stubley]

As parliament builds up to the vote on the EU withdrawal agreement on 11 December, Labour's shadow Brexit secretary has said it is inevitable that they will table a motion of no confidence in the government if the deal is voted down in the Commons.