Downing Street sources say the Tory leader does not want to take part in TV debates ahead of the snap election on June 8.
But ITV confirmed on Wednesday that it intends to hold a debate ahead of polling day, regardless.
An official statement from the broadcaster said: “ITV will hold a leaders’ debate as we did in 2010 and 2015.
"We will announce more details in due course.”
It is still unclear whether Mrs May will attend the debate but there have been calls for broadcasters to “empty chair” her if she remains a no-show.
John McDonnell accused her of “running scared” of Labour by backing away from a TV showdown.
Responding to ITV's announcement, Mr Corbyn said: "I welcome ITV's decision to attempt to hold a TV debate with the Prime Minister.
"If Theresa May is so proud of her record, why won't she debate it?
"She cannot be allowed to run away from her duty and refuse to let the British people hear the arguments directly."
No details have yet been released but the debate is expected to take place in early May and hosted by ITV newsreader Julie Etchingham.