Theresa May has failed to reveal how much the UK government would be prepared to pay for access to areas of the EU's single-market after a Brexit.
The Conservative leader repeatedly dodged the issue as she faced Jeremy Corbyn at Prime Minister's Questions (PMQs) on Wednesday (18 January).
"My question was about how much we are going to have to pay to have access to the market. Still no answer," the Labour leader said.
The House of Commons exchange comes after the prime minister promised that the UK would stop sending "huge sums" to Brussels. Britain currently pays around £135m ($165m)-a-week to the EU.
May said she was committed to getting the "best possible" free trade deal with the EU, while Corbyn warned of a "bargain basement Brexit".
"Instead of threatening to turn Britain into an offshore tax haven, let's welcome those who contribute to our public services and fund out public services properly so that we do have the fully-functioning NHS that we all deserve," he said.
But May hit back by claiming that the left-winger "doesn't have a clue" about the negotiations.
"There is indeed a difference between us – it's very simple," she said. "When I look at the issue of Brexit, or indeed any other issue like the NHS or social care, I consider the issue, I set out my plan and I stick to it: it's called leadership, he should try it some time."
The prime minister revealed on Tuesday that her government would not seek to maintain the UK's membership of the EU single-market.
May also said that she would attempt to secure a customs deal with the EU so that goods can move "frictionlessly" between the parties, but the UK would be able to broker its own trade deals.
"Whether that means we must reach a completely new customs agreement, become an associate member of the Customs Union in some way, or remain a signatory to some elements of it, I hold no preconceived position. I have an open mind on how we do it," she said.
The prime minister plans to invoke Article 50 – the mechanism to break from Brussels – and trigger talks with the EU by the end of March.
But the Supreme Court is yet to rule on whether MPs should have a vote on invoking Article 50. May has promised that Parliament will have a say on the final Brexit deal.