"The government should do the right thing and make this full advice available, with so much at stake for all our constituents, with eight days to go before the vote on the deal, this House and this country deserves better from this government", he said.
The party says it will accuse the government of being in contempt of Parliament if it does not release it.
However, the refusal to publish his full legal advice to the cabinet - despite a vote by MPs demanding it - means that six opposition parties including the DUP have begun proceedings to hold the Attorney General in contempt of Parliament.
An increasingly restless DUP is just one thing for May to worry about this week.
The pressure was deepened today after the Sunday Times published details of the advice given to Cabinet, which included a passage saying the United Kingdom could end up being locked in a "backstop" arrangement with the European Union over the border with Ireland. "They are essentially either we leave with no deal which would have serious economic consequences, or we say to the British public: 'I'm sorry you got it wrong, you're going to have to do it again, ' which I think would have serious democratic consequences". "This is the deal that will ensure that happening in an orderly way with legal certainty".
The government has said it will release a summary. "This is not Brexit".
In the increasingly likely event therefore that May loses next week's vote, Labour will nearly certainly seize on it as an opportunity to bring down her government - which is now propped up by an unsteady alliance with the right-wing Northern Irish Democratic Unionist Party (DUP), that is itself expected to vote against the deal.
Asked if she was "knackered" after a busy schedule trying to convince the public of the benefits of her deal, Mrs May said: "It's a tough time, it's a hard time.an terrible lot of work has had to go into this".
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However, that has not prevented the veteran National Basketball Association coach from taking aim at Leonard in the same breath. Leonard's reaction came less than 24 hours after Popovich referenced his former star in a comment about the Spurs' leadership.
Rather than publishing the full document, however, on Monday the government published a 43-page document summarising Cox's legal opinion instead.
A cross-party group of MPs on Thursday laid down an amendment to May's European Union withdrawal legislation in a bid to stop a no-deal Brexit emerging as the default fallback option.
Commons Speaker John Bercow has told MPs he believes there is an "arguable case that a contempt has been committed" by the Government over Brexit legal advice.
"We have therefore been left with no option but to write to the speaker of the House of Commons to ask him to launch proceedings of contempt".
If May's government lost a no-confidence vote, it would have two weeks to overturn the result with a new vote by lawmakers.
All indications are that the bill will be defeated, something that could be made more likely Monday if Labour is successful in forcing May to reveal the full legal advice she sought before agreeing the deal with European leaders last month.
Defeat could also make it more likely that Britain holds a second European Union referendum, three years after voting narrowly to leave the bloc.