The European Commission's chief negotiator is working on the basis the UK would have to pay a Brexit settlement fee of 50-60 billion euros (£42bn-£50bn) for outstanding liabilities, Sky sources say.

A bill worth "tens of billions of euros" will be one of "the first things coming up" in the Brexit negotiation after Theresa May triggers Article 50, an EU government minister told Sky News.

The Commission chief negotiator Michel Barnier has mentioned this figure to EU leaders in his tour of EU capitals.

And the same figure was mentioned to Brussels-based diplomats from the EU-27, in a meeting last month.

Image: Michel Barnier has mentioned the 50bn-60bn euro figure to EU leaders in his tour of EU capitals

A separate Sky source in a different country's leadership said: "We were told 50-60 billion euros. We were told informally at sherpa level."


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The news, which is sure to cause fury among UK Brexiteers, was communicated by Mr Barnier,

But it has not been circulated as a working paper yet.

Asked about the bill, a Downing Street spokesman said: "The UK will uphold its obligations to the EU while it is still a member but future costs are open to negotiation."

Separately Sky News has been told of another analysis of the same liabilities by two EU finance ministries, calculating a smaller but still huge "bill" at around 40 billion euros (£33bn).

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The calculation is believed to include the obligation for the UK to pay into the EU Budget until the end of 2020, having signed up to the multi-annual financial framework already.

There is also the UK's share of outstanding pensions liabilities, and other payments associated with loan guarantees.

Questioned about the huge amounts, the Czech Republic's Europe minister Tomas Prouza asked by Sky News: "I understand why the Eurosceptics call it an exit fee.

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"But this is agreeing the bills that the UK has already agreed to pay.

"We're talking about payments to the existing budget that the UK already voted for, pensions of British citizens working at the EU.

"This is only things the UK has already committed itself to paying".

When asked if British people should expect a bill worth tens of billions of pounds, Mr Prouza responded: "Definitely.

"This is what the UK has already committed to pay , and we would expect that the UK would honour its commitments ... it will be one of the first issues coming up on the table".