The Democrat Party has accused ousted premier Thaksin Shinawatra and Prime Minister Yingluck of holding secret talks with southern rebel leaders.
The allegations yesterday were bluntly denied by the Pheu Thai Party.
Mr Thaworn, who was responsible for curbing violence in the far South when he was deputy interior minister under the previous Democrat-led government, told the House Thaksin had met 18 representatives of the southern rebels in a "neighbouring country" on Feb 22 and Ms Yingluck had talked with 15 representatives of the insurgents on March 17.Days after the chief of the Southern Border Provinces Administrative Centre (SBPAC) Thawee Sodsong denied talking with separatist leaders, Democrat MP for Songkhla Thaworn Senneam claimed Thaksin and Ms Yingluck had broken the government's stance of not negotiating with the insurgents.
Democrat MP for Yala Prasert Pongsuwansiri said Thaksin was seen hugging a leader of the Pattani United Liberation Organisation (Pulo) in a picture posted on the group's website.
Opposition leader Abhisit Vejjajiva echoed Mr Thaworn's allegation, saying several items of information confirmed Thaksin had held talks with the separatists. He also warned that any involvement of the former premier would complicate efforts to end the unrest.
Deep South Watch, a non-governmental agency monitoring the southern violence, reported on its website that one of the key leaders of the separatists joining the talks with Thaksin was Hassan Toyib, a leading Pulo member.
Thaksin could not be reached for comments about his alleged involvement in the talks with the separatists. Ms Yingluck made no comment on the issue.
Deputy Prime Minister Chalerm Yubamrung strongly denied Thaksin and Ms Yingluck had negotiated with rebel representatives and called the Democrats' accusations groundless.
He said it was not the responsibility or the authority of Thaksin to solve the southern problems and called the Pulo information unreliable.
Mr Thaworn also questioned the sincerity of the government in tackling the problems in the South.
The prime minister chairs the committee under the SBPAC to work out a strategy to solve the problems in the far South. But Ms Yingluck and Mr Chalerm never attended the panel's meetings, Mr Thaworn said.
Mr Thaworn also urged the government to set up a forward command to prove its determination to restore peace in the far South and boost the morale of people and officials in the region.
He pointed out that the operations of the forward command set up by the Democrat-led government and shut down by the Pheu Thai-led administration would be more efficient than Mr Chalerm's idea of having a support unit direct authorities to work out plans to curb violence in the deep South in the wake of the weekend bombings in Pattani, Yala and Hat Yai.
Mr Thaworn was referring to the Bangkok-based support unit set up by Mr Chalerm to integrate work among state agencies.
Mr Chalerm has said the unit is situated at the Royal Thai Police headquarters.
Representatives from security agencies, including the National Security Council, Defence Ministry, and intelligence agencies would meet once a week to work measures to try to quell the southern violence, he said.
Mr Chalerm rejected the Democrats' call to set up a forward command, saying the presence of a cabinet minister would only increase the burden on security authorities in the region.
He also urged the Democrats to back the idea as the party should have useful information about the region as it is the opposition party's political stronghold.
Meanwhile, Deputy Prime Minister Yutthasak Sasiprapa said the government would impose "safety zones" that would be subject to tough security measures in the South to prevent further attacks.
He said the government had intended to impose such zones earlier in Yala province but local businessmen sought a postponement to avoid hurting tourism and trade.
He thought this leniency had raised the chance of terror attacks.
But this time Gen Yutthasak said the safety zones were necessary and would be imposed in areas that might be targeted by terrorists.
He said residents would have to be patient with the measure as it was for the sake of public safety.
The deputy prime minister did not think the present situation justified a curfew.