Downing Street has slapped down a minister who admitted the UK will be legally bound to pay its Brexit ‘divorce bill’ regardless of whether the EU agrees to a beneficial future trade deal.

Number 10 insisted that “nothing is agreed until everything is agreed” after Suella Braverman said MPs would be asked to approve the payment of some £39bn months before real detail of a trade deal is known.

Brexit Secretary David Davis has previously indicated that the UK could use divorce payments as leverage to win a more advantageous future trading arrangement with Brussels.

It was at a select committee on Wednesday that Ms Braverman admitted the UK would be legally bound to pay the bill, while it would only be “a duty of good faith” on the EU to adhere to conditions in terms of future trade.

But asked about her appearance later, Ms May’s spokesman said: “We have been absolutely clear that nothing is agreed until everything is agreed.  We are clear of our intent to agree the future framework at the same time as the withdrawal agreement.

“Article 50 sets out that the withdrawal agreement should take account of the parting member state’s future relationship with the EU.

“This means Parliament will vote on the withdrawal agreement at the same time as the terms of our future relationship with the EU.”

The spokesman did not disagree with the contention that while the UK would be legally bound to pay the divorce bill, the EU would not be bound to promises on the future trade.

Under fierce questioning at the Brexit committee earlier in the day, Ms Braverman was asked if MPs would be “agreeing the financial settlement before there is a legal treaty on the future relationship”, with the minister eventually replying, “yes”.

Pat McFadden, a pro-EU Labour MP said it exposed Ms May’s promise that “nothing is agreed until everything is agreed” to be an empty one.

During the evidence, given to the Brexit committee, ministers also confirmed that the so-called backstop – keeping the UK aligned to the EU on customs after 2020 – must be “time limited”.

The Independent revealed today that the red line has already been rejected by the EU as failing to guarantee a continued open border in Ireland – throwing the negotiations into fresh jeopardy.