A political deal involving the formation of a new government has been reached in Hong Kong between Thaksin Shinawatra and Thanathorn Juangroongruangkit, the leader of the Progressive Movement, a source in the Pheu Thai Party says.

The source said Mr Thanathorn flew to Hong Kong on Monday morning and returned to Thailand the following day.

"They discussed the possibility of the MFP [Move Forward Party] being excluded from the new government," the source said. The source did not give further details.

The Progressive Movement emerged after the Future Forward Party (FFP), which Mr Thanathorn founded and served as leader, was disbanded.

Re-emerging as the MFP, its key figures -- who were banned from participating in elections -- came together to form the Progressive Movement, which has been helping the MFP campaign for the election.

Thaksin, meanwhile, is widely believed to be Pheu Thai's de facto leader.

The revelation came after MFP secretary-general Chaithawat Tulathon dismissed a report on Wednesday which claimed the party's key figures were planning to fly to Hong Kong to meet Thaksin.

Meanwhile, massage parlour tycoon-turned-whistleblower Chuvit Kamolvisit held a press conference on Thursday in which he claimed Pheu Thai had struck a deal with Bhumjaithai and the Palang Pracharath Party (PPRP) parties to form a government with a combined 279 MPs, excluding the MFP.

He said that key figures of the parties met Thaksin in Hong Kong to strike the deal on Tuesday -- the same day Mr Thanathorn met Thaksin there, Mr Chuvit claimed.