A negotiation paper released today lays out the EU Commission's hardline stance on the UK settling its "financial obligations".
The bloc wants Britain to keep lining its pockets until at least 2021, even though divorce talks are expected to be completed in 2019.
The document fails to reveal the exact cost of the 'Brexit bill', suggesting it is willing to negotiate the eyewatering demand of £85billion (€100bn).
But it does state: "The Union and the UK should both respect in full the financial obligations resulting from the whole period of the UK membership in the Union."
It includes a four-page appendix of EU organisations the UK is expected to keep funding once it leaves the bloc.
Among them are the European Court of Justice, which Brexit campaigners claim is a threat to the sovereignty of the UK's legal system.
The EU will also demand the UK keeps paying into the budget of several schemes aimed at easing the ongoing migrant crisis.
The EU's demands for a hefty Brexit bill are likely to anger Theresa May Juncker's most cringe-worthy kisses Wed, May 17, 2017
Jean-Claude Juncker's many signs of affection
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Jean-Claude Juncker, President of the European Commission, kisss Michel Barnier
The bloc wants Britain to keep paying into the EU budget for several years
European officials have previously raised fears the UK could refuse to pay the hefty settlement and walk away without a deal.
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The EU's chief Brexit negotiator Michel Barnier admitted earlier this month that a growing number of Britons want a "disorderly exit".
Speaking during a Commission meeting, he warned this possibility "would become real" if both sides cannot strike an agreement over the exit fee.
Brussels fears UK negotiators could walk away from talks without a deal
And Brexit Secretary David Davis has settling the Brexit bill during the talks, which will begin on June 23, would be "tough".
He said: "This morning you see demands for €100bn in the papers. It has gone from €50bn, to €60bn to €100bn.
"It rather actually proves her point. I know that is not where we will end up. The simple truth is this is going to be a tough negotiation."
Brexit Secretary David Davis had admitted negotiations will be 'tough'
And he hinted the Government would follow the example of Margaret Thatcher's negotiations with European leaders.
The Cabinet minister said: "When Mrs Thatcher walked away, she got the rebate. We have a €290bn market for them.
"Once we are outside we will be their biggest external market. That's incredibly important to them. We want a deal. We think we can get a deal."