Once again, UK Prime Minister Theresa May has managed to unite pro-European Labour MPs and Brexiteer conservatives in opposition to her government by refusing to release the full 'legal advice' provided by UK Attorney General Geoffrey Cox, stoking suspicions that she is trying to hide the fact that the Brexit deal, as it's currently written, could result in the UK being stuck inside the EU customs union in perpetuity - a scenario that Brexiteers have warned would reduce the UK to a 'vassal state' of Europe.

Angry ministers have threatened everything from calling a vote of no confidence in the government to holding Cox in contempt if No. 10 Downing Street doesn't authorize the release of the unabridged legal advice. But in an act of defiance, May on Monday released a 43-page summary of the AG's advice that one reporter said appeared to leave out most of the AG's most controversial findings.

Legal advice summary contains none of the dire warnings we have been told the full text does. Underlines mutual decision of the joint committee on the backstop. No real detail on financial liabilities under transition extension/backstop. — Jessica Elgot (@jessicaelgot) December 3, 2018

As we noted earlier, a leaked analysis shows that May lied to lawmakers when she said there was no risk of the UK being trapped inside the customs union. As the Guardian explains, while the text of the withdrawal agreement clearly states that any end to the 'backstop' must happen by consensus (which, assuming the backstop is eventually triggered, would happen once a new trade deal has been reached) between the UK and the EU. So Brexiteers' warnings have a clear basis in the text of the agreement. However, many MPs are suspicions that AG Cox was more negative about this in private than he has been in public.

Some Labour MPs have warned that, by refusing, May has risked sparking a constitutional crisis. This is because MPs voted last month to force the government to release the legal advice "in full". But May has effectively ignored these demands and continued to withhold Cox's unabridged advice. The controversy has prompted at least one conservative MP, Sam Gyimah, to quit his cabinet post in protest, saying that releasing the unabridged advice is vital to "restoring trust in politics," according to the BBC.

As we noted yesterday, Labour Shadow Brexit Secretary Keir Starmer has warned that "If they don't produce the advice...this will be a collision course between the government and Parliament." Members of the DUP, the party from Northern Ireland that helps prop up May's government, has threatened to side with Labour in sabotaging May's government if the AG's complete analysis of the "Irish Backstop" isn't released.

Labour has clearly communicated that it plans to try and call a general election if the fulll legal advice isn't released.

Conservative MP Barry Gardiner told the BBC's Andrew Marr that the prime minister faced a "very serious constitutional crisis" if she withheld the advice, and raised the possibility of another general election.

In what is expected to be a marathon Q&A session, Cox is appearing before Parliament Monday afternoon to answer questions from MPs, beginning at 2 pm local time.

But regardless of what is said, May and her cabinet have made it abundantly clear that they have no intention of allowing the 'legal advice' controversy delay the vote. Home Secretary Sajid Javid has dismissed speculation that the planned Dec. 11 vote could be delayed.

A five-day pre-vote debate period is expected to begin on Tuesday.

Read the full legal advice summary below:

EU Exit - Legal Position on the Withdrawal Agreement by Zerohedge on Scribd