Sri Lanka is considering a referendum on its Norway-backed peace bid with the Liberation Tigers of Tamil Eelam, as the dialogue process has moved to highly contentious issues, Constitutional Affairs Minister G L Peiris said on Thursday.

He did not say when the referendum would be held, but the move could be aimed at President Chandrika Kumaratunga, who is a critic of the government's handling of the peace process, Asian diplomats said.

"It has been suggested that it will probably be useful for a referendum to be held on a peace bill setting out the steps that we need to take to carry forward the peace process to prepare a new constitution," Peiris said.

The government and the LTTE are set for another round of negotiations in Thailand from April 29 to May 2.

Any settlement with the LTTE requires a referendum, but what the government is proposing is another plebiscite that would test public opinion before going in for drastic constitutional changes, officials said.