The British Prime Minister Theresa May says Brussels is going to take a "tough" approach in the Brexit negotiations.
The remaining 27 countries yesterday agreed their strategy for the talks.
EU leaders say the UK must negotiate its exit from the union - before beginning talks on trade.
Speaking to the BBC's Andrew Marr Show, Theresa May said that stance means she needs a strong mandate from voters in the UK election:
"And we've already seen some of the comments that have been coming out of Brussels which show that at times these negotiations are going to be tough.
"So in order to make sure that we get the right result, the best deal for this country, the deal that's going to work for people across the country, we need to ensure that we've got a strong hand in that negotiation," she said.