What happens if the government loses the vote? Ashley Cowburn, our political correspondent, has taken a look at the ramifications.
Politically, it would be a major embarrassment for Theresa May’s government – the first in modern history to be found in contempt of Parliament. Hardly good timing for the prime minister, who today also kicks off the first of five days of debates on her Brexit deal.
On a practical level, the cross-party motion, if passed, will demand ministers publish the “full and final” legal advice on Ms May’s deal.
So far ministers have resisted such calls, even after a Commons motion was passed around two weeks ago requesting the government do so.
But a motion of contempt would ratchet up pressure on the prime minister to publish the legal advice – not just as “position statement” as was the case on Monday.
The motion does not place sanctions on individual ministers, but if the government again refuses to publish the legal documents upon losing the contempt motion, it appears likely the opposition parties in Westminster will push for further sanctions.
This could be brought against senior ministers in the government – most likely David Lidington, the cabinet office minister, or Geoffrey Cox, the attorney general. These ministers could face suspension from the chamber – and potentially miss the “meaningful vote” on the PM’s Brexit deal next week.