Mr. Corbyn, who had refused to participate in the televised debate in Cambridge with officials from seven parties because Prime Minister Theresa May had declined to do so, made the announcement on Wednesday at a rally in Reading, west of London.
“I have to go now,” Mr. Corbyn said, “because I am going to Cambridge to get ready for the debate, because there is no hiding place.”
The debate begins at 7:30 p.m. local time.
The Labour Party is expected to fare poorly in the general elections on June 8, but it has gained ground in recent polls, putting pressure on Mrs. May and her Conservative Party.
“Refusing to join me in Cambridge tonight would be another sign of Theresa May’s weakness, not strength,” Mr. Corbyn said in a statement.
Home Secretary Amber Rudd was expected to represent the Conservatives at the debate, and the party said in a statement that it would not follow Mr. Corbyn’s lead with an 11-hour reversal.
“There are no changes to the prime minister’s plans,” the campaign said in a statement, according to the British news media. “She is out campaigning today, engaging with voters about the issues that matter, not swapping sound bites with six other politicians.”
Mr. Corbyn and Ms. Rudd are expected to be joined by representatives of five other parties: Tim Farron of the Liberal Democrats, Angus Robertson of the Scottish National Party, Paul Nuttall of the U.K. Independence Party, Caroline Lucas of the Green Party and Leanne Wood of the Welsh nationalist party, Plaid Cymru.