Democrat MP for Surat Thani Suthep Thaugsuban is claiming ousted prime minister Thaksin Shinawatra sent a representative to approach him for reconciliation talks.
However, Mr Suthep did not disclose the name of Thaksin's alleged representative.
A source in the opposition party said Thaksin made contact with Mr Suthep through one of the former 111 Thai Rak Thai executives last week.
Mr Suthep yesterday told the Bangkok Post that he is suspicious of Thaksin's commitment to fostering reconciliation in the country.
"It is pointless to hold talks with Thaksin because he will go back on his word again. It will be hard for me to explain to people close to me and to my voters.
"To be frank, I've been fooled several times. It would be a shame to be [fooled] again," Mr Suthep said.
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Mr Suthep said he has asked the "coordinator" to pass on some advice to the deposed prime minister in a goodwill gesture.
The Democrat MP said he has asked Thaksin to back down on his plans to push for the charter rewrite and trying to whitewash his wrongdoings through a reconciliation bill.
"If the constitutional amendment and reconciliation bids are stopped, there will be no grounds for fresh political tension," he said.
Mr Suthep said he has also urged the former prime minister to allow the Pheu Thai-led administration a free hand in running the country.
The Democrat MP said he is confident that the Yingluck Shinawatra cabinet is politically stable and capable of completing its four-year term if it is free of pressure from Thaksin.
Mr Suthep has suggested that Thaksin hold talks with red shirts and cut ties with the hardcore ones or more damage would be inflicted upon the country.
"If he can do so, half of the red shirts may end up joining Pheu Thai. When they [the hardcore] don't receive financial aid, they will be less dangerous to the country," Mr Suthep said.
Mr Suthep has also asked Thaksin to stop his support for what he claimed was the training of armed groups for use in inciting violence.
"I gave him my advice through the contact last week. I have no idea if he will listen," Mr Suthep said.
Meanwhile, a source in Pheu Thai admitted yesterday that attempts have been under way to negotiate with the Democrat Party, especially Mr Suthep.
The source said the Democrats have constantly rejected Pheu Thai. But the ruling party saw no point in having enemies after its election victory.
"We've entered negotiation mode but our efforts are futile. Mr Suthep thinks he has the upper hand and rejects holding talks," said the Pheu Thai source.