0109 GMT March 26, 2019
Scottish National Party (SNP) lawmaker Ian Blackford was twice reprimanded by the House of Commons speaker for suggesting May had misled MPs "inadvertently or otherwise", before withdrawing the claim, AFP reported.
May replied that she had always been clear about the implications of the deal's provisions on Northern Ireland, which risk keeping Britain tied to the EU's economic rules for years after leaving next March.
But she emphasized neither side wanted this to happen, and repeated that the withdrawal agreement struck with Brussels last month was the only viable option.
May on Tuesday suffered a series of stunning defeats in Parliament which threaten her government and ultimately could change the course of Brexit.
She effectively lost her majority in the Commons after the Alliance Party of Northern Ireland on which she relies sided with the Labour Party to find her ministers in contempt of Parliament for failing to publish in full the legal advice on the Brexit deal.
Meanwhile, 25 of her own Conservative MPs voted with Labour to give the Commons a bigger say in what happens if, as expected, the Brexit deal is voted down on December 11.
The government on Wednesday finally published the six-page advice from the attorney general to cabinet, which warns of the "legal risk" inherent in a clause intended to keep open the border with Ireland.
It confirms Britain risks remaining "indefinitely" in the so-called backstop, which could keep the whole country in an EU customs union for years after Brexit, while also keeping the province of Northern Ireland in the bloc's single market.
MPs on Tuesday also voted to approve an amendment tabled by Conservative former attorney general Dominic Grieve, which allows Parliament to determine what happens if the deal falls.
If May loses the vote next week, the government has 21 days to return to MPs to propose what happens next.
Grieve's amendment could allow MPs to amend that statement, raising the possibility they could demand a renegotiation, a second referendum or even staying in the EU.
International Trade Secretary Liam Fox aired that concern, saying that a majority in favor of staying in the EU in Parliament "may attempt to steal Brexit from the British people".
May opened the first of five days of debate on the Brexit deal on Tuesday evening and Wednesday's discussion was to focus on security.
On Tuesday, opposition Labour leader Jeremy Corbyn called May's plan "a huge and damaging failure for Britain".
There are few people who believe May's deal will survive the vote next Tuesday but the question of what happens next remains wide open.
Some Conservative MPs are pushing for a second referendum, with a choice of staying in the EU.
But May warned on Tuesday that another Brexit vote would do nothing to settle bitter debates about Britain's place in Europe that have raged since it joined the bloc in 1973.
"We cannot afford to spend the next decade as a country going round in circles," she argued.
Many MPs want May to return to Brussels to renegotiate her deal, and she is due at a summit two days after next week's vote.
However, EU leaders have repeatedly said they will not reopen the divorce deal.
In Brussels, the European Commission on Wednesday began the process of ratifying the Brexit deal.
Some eurosceptic Conservatives believe Britain can leave without any deal at all, although a government assessment last week found this risked causing a major recession.
If her deal fails, May would likely face a confidence vote in the Commons, or a challenge by her own Conservative MPs.