She called on other leaders to chip in. How much do they need? And where does the money come from?

Matichon recently calculated that the average cost per constituency in the 2005 election was Bt20 million, shared half-half between the candidate and the party. That would make the Thai Rak Thai Party's share about Bt4 billion for the whole country.

Besides these campaign costs, the party also needs a regular budget. Most Thai Rak Thai MPs are said to receive a regular monthly retainer from the party or their faction head. One senator recently said that some 70 to 80 of the previous senators were also on the payroll. These payments have been estimated as high as Bt200,000 per head per month, but Matichon plumped for a more conservative estimate of Bt50,000. On top of this there are large publicity costs. Political leaders and political parties no longer advertise themselves only at campaign time, but keep up a constant drip-feed of ads, just like detergent brands. Then there are the operating costs of Thai Rak Thai's splendid big building. With sundries, this must all add up to Bt2 billion to Bt3 billion a year.

Thai Rak Thai's exceptional presence in Thai politics over the past six years has been underwritten by exceptional amounts of cash. Where does this come from? Since the party's foundation, Pojaman has been the largest donor according to official figures. But her generous largesse nowhere near covers the estimated budget for the party's operating expenses and election campaign costs. Other leaders of this billionaires' party have chipped in. In 2005, party-list candidacies and minister posts were awarded to some big moneybags, including alleged stock market fraudsters. Still, it's difficult to account fully for Thai Rak Thai's massive financial power in Thai politics.

Recently a suggestion appeared in the fourth of the series of "Ru Than Thaksin" (Understanding Thaksin) books edited by former senator Chirmsak Pinthong. This volume is subtitled "The Insiders", though "The Rat Laundry" might have been more appropriate. Four former supporters of Thaksin explain why they have defected (ratted), and try to justify (launder) their past actions in supporting him.

The longest confession is from Snoh Thienthong, who truly qualifies as an "insider". He was formerly adviser, whip, and deputy leader of the Thai Rak Thai Party, and number 18 on the Thai Rak Thai party list in both 2001 and 2005. He connived with Thaksin in the infamous land deal over the Alpine golf course, and has often claimed to be the kingmaker who put Thaksin in power.

In this book, Snoh makes the following allegation.

"He placed one of his own people in every ministry. These people did not need to have a powerful post, but everybody knew who they were ... If any minister wanted to propose a project using the central budget, the minister would first have to clear it with 'his person' first. Many ministers were approached by 'his person' saying, 'The budget is coming. You can have five or six billion, but 10 per cent must go to the party ... Any minister who would not do this, could not remain."

Snoh then explained how the system worked.

"For this 10 per cent policy, the minister would have to pad the budget proposed for approval to include the 10 per cent that would go to the party. Then once it was agreed with 'his person' via Khunying, the matter could be sent to his trusted 'permanent political representative', who used to be his company employee. To date nobody knows how much this 10 per cent amounts to. Probably need to ask Khunying."

Snoh claims to have asked Pojaman what she needed so many billions for, and got this answer: "In politics you have to hand out money. It has to be considered a business." Snoh asked her what would happen if things blew up, and she replied, "If Thaksin falls, the Thai Rak Thai Party will have to stay in power for at least two more terms for safety."

Of course, allegations over percentage commissions on budget projects are nothing new at all. It is other aspects of this allegation which make it so arresting.

First, the centralisation. We are used to hearing about gangs of ministers, senior officials, and businessmen conspiring to take a percentage on budget projects through overpricing and similar devices. But this allegation suggests another subtraction which supplants or (more likely) supplements that form of corruption. We are told there is a centrally directed network that reaches into "every ministry". Ten per cent of the total capital budget is about Bt20 billion.

Second, the proceeds are allegedly channelled to the Thai Rak Thai Party. In other words, Snoh alleges that the party's massive financial strength is financed by the taxpayer.

Is Snoh credible? He's a very old-style politician. He gave Thaksin considerable help and has a lot to excuse himself for. He has been gradually sidelined by Thaksin over the past five years, and has reasons for feeling aggrieved. He still has political ambitions and has already launched his own new party. His allegation could be seen as nothing more than another move in the political chess game.

But that makes it all the more extraordinary that the accusation has brought forth no pained denial, no counter-charge, and none of the defamation suits which have become the confetti of Thai politics. This allegation was not some careless words heard by a few people. It was not one of those newspaper reports that the speaker can deny on the following day and blame on journalistic incompetence. It appeared in print in a signed article in a book that has quickly become very popular. Is there silence because Snoh is so lacking in credibility that denial is deemed unnecessary? Or is he too close to the truth for comfort?

Chang Noi