A report in the Financial Times newspaper today said that the EU had raised the Brexit divorce bill to an upfront payment of up to 100 billion Euros. But Britain's Brexit Secretary David Davis has rejected the idea that his country would foot such a big bill.
The 'Brexit Bill' is just one of a number of potential sticking points for both sides when it comes to negotiating the UK's exit from the European Union.
So will a deal which works for both the UK and the EU be possible?
A question for the US economist Irwin Stelzer, at the Hudson Institute in Washington.