In public, Britain and the European Union say they want an amicable divorce. Behind the scenes, things are getting nasty.

Prime Minister Theresa May acknowledged Tuesday that Brexit "will not be easy," after EU officials accused Britain of underestimating the complexity of the task ahead.

Taking aim at Britain, European Parliament Brexit coordinator Guy Verhofstadt tweeted: "The clock is ticking — it's time to get real."

Formal divorce negotiations are due to begin after Britain's June 8 election. Evidence is mounting that the two sides' expectations are poles apart.

Last week May met European Commission President Jean-Claude Juncker for a working dinner that both sides called "constructive."

But Germany's Frankfurter Allgemeine Sonntagszeitung newspaper later quoted Juncker as saying he left the meeting "10 times more skeptical than I was before."