Thai Prime Minister Abhisit Vejjejiva has accepted to negotiate with four anti-government core leaders, Minister to the Prime Minister's Office Satit Wongnongtaey said Sunday.

"But, the negotiation should be organized under a good atmosphere," Satit told state-run NBT Television.

The premier has accepted to negotiate with the red-shirted leaders in a bid to bring peace back to the country and for the national interest, said Satit.

The premier has assigned Korbsak Sabhavasuthe, Prime Minister's secretary-general, to prepare a schedule, venue, and framework of the negotiation between the red-shirted core leaders and the premier.

Other media reported earlier that an anti-government core leader gave an hour of ultimatum for a House dissolution to Prime Minister Abhisit.

In a related development, red-shirted core leaders said they have agreed to enter the peace negotiation with the prime minister, which will be preliminarily held at King Prajadhipok's Institute.

The four red-shirted leaders to negotiate with Abhisit are Veera Musikapong, Jatuporn Prompan, Nattawut Saikua, and Weng Thojirakarn.

Nattawut said "we hope that the prime minister will be sincere to negotiate with us."

The red-shirted stance has remained that the premier should dissolve the lower House of parliament, Nattawut said.