The government has admitted to the possibility of being sued but has insisted on going ahead with a plan to collect an estimated 16 billion baht in tax and fines from former prime minister Thaksin Shinawatra over the Shin Corp stake sale.
Deputy Prime Minister Wissanu Krea-ngam said Wednesday the Revenue Department will proceed with the tax collection process before the statute of limitations in the case expires on March 31.
According to Mr Wissanu, the government has found a "miracle of law" to collect the taxes, which should "be worth a try".
He said the Revenue Department would start the process of tax and fine assessment against Thaksin before March 31, causing an end to the existing 10-year statute of limitations and a new 10-year statute of limitations to begin.
Still, Mr Wissanu admitted it was possible the Revenue Department could be sued by Thaksin following the move. However, he expressed confidence the government would win the case eventually.
The deputy prime minister added there is no need to provide revenue officials with immunity in pursuing the case against the deposed premier, adding the tax collection process will follow the existing tax code.
Thaksin has 30 days to appeal the tax evaluation claim, he said.
Mr Wissanu's assurances the government would collect the tax came after his meeting with the Revenue Department which has been assigned to explore legal avenues to collect the tax.
According to department sources, the tax and fines against Thaksin could reach 16 billion baht.
The matter concerns Thaksin's adult children, Mr Panthongtae and Ms Pinthongta, who bought 329 million Shin Corp shares at a price of one baht each from Ample Rich, an offshore holding company controlled by the Shinawatra family.
The pair later sold the shares in their name to Temasek through the Stock Exchange of Thailand for 49.25 baht each, reaping a capital gain of nearly 16 billion baht.
The Revenue Department demanded the siblings pay several billion baht in personal income tax assessed on their sale of Shin Corp shares. The tax on the capital gains along with the fines for not paying it totalled about 12 billion baht at the time.
The case went to the Central Tax Court which ruled in the siblings' favour and the Revenue Department did not appeal against the ruling.
According to the court, the real owner of the shares was Thaksin, not his two children.
Based on the ruling, the Office of Auditor-General (OAG) asked the Revenue Department collect the 12 billion baht in tax from Thaksin.
Some critics argue that Thaksin's assets were seized so he was no longer liable to pay taxes.
Mr Wissanu said Thaksin's tax liability is separate from the seizure of his assets worth 46 billion baht ordered by the Supreme Court's Criminal Division for Holders of Political Positions.
"The OAG insists the taxes must be paid. So the government has instructed the Revenue Department to consider the 'channels' that will be argued in court if the taxes should be paid or not," Mr Wissanu said.
Auditor-General Pisit Leelavachiropas said a tax collection summons had been issued to Thaksin's children and was based on the Supreme Court's ruling that the children acted as nominees of Thaksin. According to the Civil Act, the summons is tantamount to one for Thaksin.
As a result, the five-year time frame that is stipulated by the Revenue Act for tax collection against Thaksin has been fulfilled, he said.
By law, people who have incorrectly submitted their annual earnings for tax evaluation will not be required to resubmit them after five years pass.
Previously, the Finance Ministry's tax committee, chaired by deputy permanent secretary for finance Prapas Kong-ied, said the five-year time frame, which expired in 2012, will not be extended.
"This is not a 'tactic' but a legal avenue that can be used to collect the tax," said Mr Pisit.
He said the office is ready to do the tax evaluation if the Revenue Department is not.
A source at the Revenue Department said the tax collection process will be based on the ruling by the Supreme Court's Criminal Division for Holders of Political Positions.
Sathit Rangkhasiri, former chief of the Revenue Department, may face an investigation because he did not appeal the Tax Court's ruling despite a recommendation to do so by former deputy permanent secretary Supa Piyajitti.
Noppadon Pattama, a close aide to Thaksin, Wednesday questioned what basis would be used to demand the taxes from the former prime minister.
He said the tax dispute involving Thaksin and his two children does not concern the statute of limitations, but rather the capital gains from selling the shares on the stock market to Temasek Holdings.
Mr Noppadon said the Revenue Department is a tax specialist and he hoped that the officials concerned would strictly adhere to the law.