
Prasong denied having health problems or entertaining thoughts of stepping down anytime soon.
Earlier in the day, MP Chaiyot Jiramethakorn, Prasong's colleague from the coalition Puea Pandin Party, told a press conference at Parliament that Prasong had resigned as deputy interior minister, due to health problems.
Chaiyot even produced a handwritten resignation letter with Prasong's signature.
Prasong admitted writing the letter but explained it was written before he had assumed the Cabinet post as required by his political party.
Asked about Chaiyot's motive for calling a press conference to announce his resignation, Prasong said Chaiyot might be keen on replacing him.
But he said he had discussed the matter with "party elders" and learned they did not support any such ambition on the part of Chaiyot.
"The elders must clear up any misunderstanding," he said. "Give me a few days and I'll be able to clarify this."
At yesterday's press briefing, Chaiyot said he had also wanted to give younger people from the party an opportunity to work in the Cabinet. He also said Prasong wanted to focus more on his family business, which had been affected by the global economic downturn.
Alongkot Maneekat, a Puea Pandin MP from Nakhon Phanom, told reporters the party leader and other executives had decided to nominate Chaiyot as Prasong's successor.
Alongkot said that as someone with a background in medicine, he was aware that Prasong was "ill with many health problems".
Puea Pandin deputy leader Pan Puengsujarit said the matter was not discussed at a party meeting yesterday morning.
A party source said a faction led by Pinij Charusombat wanted to pressure Prasong to step down and as deputy interior minister in favour of Chaiyot.