LONDON — The speaker of Britain’s House of Commons, John Bercow, who gained a degree of celebrity by repeatedly challenging Prime Minister Theresa May’s Brexit agenda, has said that he will remain in his post to see the country through the crisis, increasing the likelihood of a constitutional confrontation over the country’s withdrawal from the European Union.

In a speech in Washington on Tuesday, Mr. Bercow scoffed at the idea that Parliament would allow 10 Downing Street to chart the country’s course out of the bloc, calling it “for the birds.”

“The idea that Parliament is going to be evacuated from the center stage of the debate is unimaginable, is simply unimaginable,” he said. He also told the British newspaper The Guardian that he had never committed to leaving this summer, as has been widely reported.

“I do feel that now is a time in which momentous events are taking place and there are great issues to be resolved,” he said. “In those circumstances, it doesn’t seem to me sensible to vacate the chair.”