The rebel Liberation Tigers of Tamil Eelam (LTTE) said they would open talks only on the basis of a self-rule plan seeking an Interim Self-Governing Authority (ISGA) in embattled areas.
"Sri Lanka's Tamil Tiger rebels have dismissed new government proposals to restart peace talks," the BBC reported on Monday.
The BBC's Tamil language service quoted the LTTE's political wing leader SP Thamilselvan, who is currently visiting Europe, as saying they were shocked by reports of government proposals.
The government announced on Thursday that it had finalised its counter proposals and was ready to present them to the Tigers.
A state-run media report said talks could resume early next month.
But Thamilselvan reiterated the LTTE's public stance that they were not willing to negotiate unless the government agreed first to discuss their ISGA proposal.
"Thamilselvan categorically denied that peace talks would resume next month on the basis of that [government] blueprint," the BBC said.
"He also accused the government of sending out conflicting and confusing signals."
Kumaratunga has called for
peace talks to resume
The Sunday Observer, a state-run newspaper, said the stalled peace talks would resume early next month, ending an 18-month deadlock in the Norwegian-backed process.
A top official from President Chandrika Kumaratunga's office visited the rebel-held town of Kilinochchi on Saturday, amid signs the peace process was being re-activated.
However, Thamilselvan told the BBC that none of their top-level leaders had met any government representatives recently.
There was no immediate reaction from the Colombo government to Thamilselvan's latest remarks.
Despite the stalemate in the peace talks, both sides have maintained the Norwegian-brokered ceasefire that has been in place since February 2002.
However, the government has accused the Tigers of systematically eliminating political opponents, a charge the rebels deny.
Up to 60,000 people have been
killed in the island's civil war
President Kumaratunga earlier this month invited the rebels to discuss setting up a federal state in exchange for peace.
Her government's main coalition partner, the Marxist JVP, opposes any territorial concessions to the Tigers, and opposition parties have demanded a united front to push ahead with the peace process.
Sri Lanka's civil war between Colombo and the country's Tamil rebels has claimed up to 60,000 lives in the past 20 years.