According to reports, Mr Suthep made the announcement on a PDRC rally stage on Thursday.
He said he is ready to represent the great mass uprising, or muan maha prachachon, in talks with Ms Yingluck, so long as they are the only two that take part in the debate.
The talks must also be broadcast live on television stations nationwide so people throughout the country can bear witness, he said.
"Just tell me the date and time. But the talks must be one-on-one and broadcast live on all television channels to allow people all over the country to hear," Mr Suthep said.