Mr Rees-Mogg queried the controversial divorce bill as Mrs May faced major opposition to her Brexit plans from across the House. The leading Brexiteer asked the Prime Minister if she had forgotten a House of Lords report in 2017 which said no divorce bill would be required if the UK left the bloc without a deal.
And Mr Rees-Mogg – who leads the influential European Research Group – questioned what Britain was getting in return for the massive divorce bill.
The North East Somerset MP said: “The Prime Minister said we had a legal obligation to pay £39 billion.
“I wondered if she’s forgetting the House of Lords report from March 2017 that said in the event of leaving without a deal we don’t owe any money at all, therefore what are we buying with £39 billion of taxpayers’ money?”
In response, Mrs May insisted that she had not forgotten the Lords report but there was a different opinion.
The Prime Minister added: “That opinion was there are legal obligations this country would hold to the EU in relation to financial payments in any circumstances.”
Mrs May faced an onslaught of questions from ministers, with former foreign secretary Boris Johnson arguing that the Prime Minister’s deal does not give businesses certainty.
Mr Johnson said: “It’s very hard to see how this deal can provide certainty to business or anyone else when you have half the Cabinet going around reassuring business that the UK is effectively going to remain in the customs union and in the single market, and the Prime Minister herself continuing to say that we are going to take back control of our laws, vary our tariffs and do as she said just now, real free trade deals. They can’t both be right: which is it?”
The Prime Minister revealed during the session that the Commons would vote on her Brexit deal on November 11.
The debate comes after EU leaders took just 40 minutes to approve the agreement at a summit in Brussels on Sunday.
But Mrs May is facing a tougher task to push the deal through Parliament and is set to push hard over the next two weeks to win over MPs.
More than 80 Tory rebels have vowed to vote against it, while Labour leader Jeremy Corbyn has said his party will not support the deal.
And the DUP – who Mrs May relies on for her Commons majority – is also set to oppose it.