Speaking to reporters shortly after the court ruling was announced, Mr. Bercow said that lawmakers would return to the Commons at 11:30 a.m. Wednesday. Lord Fowler said on Twitter that the Lords would resume at 3 p.m.

Mr. Bercow, who has been a vocal opponent of Mr. Johnson’s decision to suspend Parliament, said he welcomed the court’s “unambiguous decision” and noted that he had been in touch with party leaders to inform them that business would resume.

Mr. Johnson planned to hurry back to London from New York, where has been attending the United Nations General Assembly, and officials said he would fly back on Tuesday night, rather than Wednesday morning.

Mr. Bercow said Parliament would skip a session of prime minister’s questions that is usually held on Wednesdays, but added, “There will be full scope for urgent questions for ministerial statements and for applications for emergency debates.”

Had the suspension been upheld, it would have meant that Parliament’s return in October would have been a new legislative session, and that any leftover bills would die. Mr. Johnson scheduled a queen’s speech on Oct. 14 to lay out the government’s agenda for the new session, which then would have been subject to days of debate, leaving even less time for Brexit.

Instead, the Supreme Court ruling means the suspension never happened, so the old legislative session is still underway, and bills that were on the table can continue through the approval process. The queen’s speech and the formal introduction of the government’s agenda are on hold.