Britain's Prime Minister Theresa May welcomes Head of the European Commission, President Jean-Claude Juncker to Downing Street in London, Britain April 26, 2017. Reuters LONDON — The European Union will demand a €99.6 billion (£87 billion) Brexit divorce bill from the UK, according to details of a secret briefing leaked to the Financial Times.

Estimates presented by the European Commission to the 27 remaining states ahead of official negotiations indicate that Brussels will demand €86.4 billion (£75.5 billion) from the UK to honour financial commitments it made as a member state.

Additionally, negotiators will demand that Britain takes on €11.5 billion of contingent liabilities, which are essentially payments that would only be triggered in specific circumstances, such as Ukraine defaulting on its EU loan.

The bill demanded by EU member states has inflated significantly in recent months as countries including France and Poland adopted a much tougher stance on Britain's financial commitments after Brexit.

While the EU wants Britain to pay a large up-front settlement as part of Brexit talks, the net total would fall over time as Britain receives reimbursements from the bloc once it has left. The Commission estimates the net figure to be €60.2 billion.

Brexit talks are due to begin on Monday despite ongoing political stability within the UK. Theresa May's Conservatives lost their majority in last week's election, forcing them to seek out a deal with Northern Ireland's Democratic Unionist Party.

That deal will not be finalised until next Wednesday at the earliest, meaning that the UK will begin formal Brexit talks without an official government.

The Commission's opening demands are expansive and unlikely to be the same as the final settlement deal. Britain is understood to be seeking a significantly smaller exit bill.