Theresa May has been urged to settle Britain's debts to the European Union (EU) in order to maximise the chances of securing a competitive free-trade deal.

A day the prime minister prepares to trigger Article 50, there has been much debate as to whether or not Britain should pay £50bn ($63bn) in obligations to the union, dubbed the Brexit divorce bill.

Some have argued Britain has no legal requirement to pay, but pro-EU ministers have warned that failure to settle would erode trust in negotiations and give European countries greater incentive to walk away.

Among the leading voices is Conservative MP Neil Carmichael who campaigned to remain.

"If we're going to row about money all the time, then we're not going to find ourselves in the right kind of relationship," he told the Guardian.

"Some of this money is about the support that we have been giving to eastern European and that's been good for them and good for all of us. We don't want to sour the relationship."

Ben Howlett, the Conservative MP for Bath, said: "We need to prioritise a free trade deal over absolutely everything else and we will be saying that to the prime minister."

The words of caution come as May's Brexit Secretary David Davis insisted the UK would not pay a sum as high as £50bn.

Appearing on a Brexit edition of the BBC's Question Time on Monday (27 March), he said: "I don't know about £50bn. I've seen £40bn, £50bn, £60bn – I've seen no explanation for any of them.

"The prime minister said we are coming to the end of the time when we are paying enormous sums to the European Union. Of course, we have our international obligations, but we expect also our rights to be expected too, so I don't think we're going to see that sort of money change hands."

However, former Deputy Prime Minister Nick Clegg insisted otherwise. "If you run up a tab behind a bar, for years and years and years, and you haven't paid when you want to leave, you settle up," he said.

A leaked draft copy of the EU's negotiating position on Brexit has shown that Britain will be threatened with court action in the International Court of Justice at The Hague if May refuses to pay the £50bn bill.