“These negotiations are difficult enough as they are. If we start arguing before they even begin they will become impossible,” Tusk told a Thursday news conference alongside Norway’s prime minister.
“The stakes are too high to let our emotions get out of hand, because at stake are the daily lives and interests of millions of people on both sides of the Channel,” the former Polish premier said.
“We must keep in mind that in order to succeed we need today discretion, moderation, mutual respect and a maximum of goodwill,” he added.
The remarks came hours after European Parliament President Antonio Tajani insisted that “no one is trying to influence the outcome of the election campaign in the United Kingdom.”
On Wednesday, May accused the EU of using Brexit as an excuse to influence the outcome of Britain’s upcoming general election.
Speaking after a meeting with Queen Elizabeth II, May told reporters at 10 Downing Street that the “bureaucrats of Brussels” were hoping to sway voters by making “threats” against the country.
She also attacked the European media, saying they had “misrepresented” her government’s stance on negotiations concerning the UK’s withdrawal from the EU.
Juncker’s chief spokesman played down May’s comments on Thursday, chalking them up to election campaign rhetoric.
“We are not naive. We know there is an election taking place in the United Kingdom,” Margaritis Schinas said.
Juncker had reportedly warned May during last Wednesday’s dinner that the negotiations will not start until London pays an alleged amount of £60 billion on its “divorce bill” and clarifies the future of EU citizens residing in the UK.
May later on dismissed the claims as “Brussels gossip.”
She has been busy campaigning for a snap general election she called for late last month.
While May insists that the vote is necessary for her to gain a stronger foothold in the negotiations, analysts say her decision was an opportunistic move to suppress opposition from Labour and win a more dominant majority in the parliament.
The British prime minister is faced with fierce competition from Labour leader Jeremy Corbyn, whose party has been steadily eating to the ruling Tories’ comfortable lead in polls over the past weeks.
Corbyn, a firm opponent of Brexit, says May should not get a free pass over Brexit and ignore Parliament’s demand during the process.
May, on the other hand, says the government should handle the negotiations on its own and present the final deal to the lawmakers.