Donald Tusk, the outgoing president of the European Council, made the stark comment Wednesday during a speech in Belgium centered on rallying opponents of Brexit ahead of Britain’s planned January 31 withdrawal.
"One of my English friends is probably right when he says with melancholy that Brexit is the real end of the British Empire,” Tusk said, according to Sky News.
Tusk added that he has “heard repeatedly from Brexiteers that they wanted to leave the European Union to make the United Kingdom global again, believing that only alone, it can truly be great.”
But “only as part of a united Europe can the U.K. play a global role, only together can we confront, without any complexes, the greatest powers of this world,” Sky News quoted him as saying.
"I have heard the same in India, New Zealand, Australia, Canada, and South Africa; that after its departure, the U.K. will become an outsider, a second-rate player, while the main battlefield will be occupied by China, the United States, and the European Union,” Tusk concluded.
Tusk’s remarks were not the first time he has ripped those in favor of Brexit.
In February, he said "I’ve been wondering what that special place in hell looks like for those who promoted Brexit without even a sketch of a plan of how to carry it out safely," according to The Sun.
Meanwhile, Britain’s Brexit Party on Thursday rejected an electoral pact with the ruling Conservatives, saying it will field 300 candidates in next month's election to force Prime Minister Boris Johnson to deliver on promises of a clean break with the European Union.
Brexit Party leader Nigel Farage says the party had to contest the seats to keep pressure on Johnson, rebuffing Conservative arguments that doing so risks splitting the pro-Brexit vote and helping parties that want to remain in the EU. His comments came on the final day for candidates to register for the Dec. 12 election.
"What we've got so far in this campaign is for Boris to promise to change direction, what we now have to do is to hold him to account to make sure we get a proper Brexit, and that's my job,” Farage said.
Britain is holding a national election on Dec. 12 because Johnson wants to secure a majority so he can take the U.K. out of the bloc by Jan. 31. All 650 seats in the House of Commons are up for grabs.
Johnson has reached a Brexit deal with the EU but has not persuaded enough British lawmakers to pass it. The single-issue Brexit Party, meanwhile, prefers to leave the EU without a deal.
The Associated Press contributed to this report.