The People's Network for the Reform of Thailand and allied groups on Tuesday petitioned the prime minister and finance minister, demanding urgent enforcement of a tax collection case involving former prime minister Thaksin Shinawatra over the sale of Shin Corp shares worth 17.6 billion baht.
Around 40 demonstrators, led by Phichit Chaimongkol, gathered at Government House to submit the petition.
The group raised two main demands, including accelerating tax collection linked to the sale of shares in Shin Corp to protect state interests.
The protesters cited a Supreme Court ruling last year that dismissed a civil lawsuit filed by Thaksin against the Revenue Department.
They said the ruling made the tax assessment order legally binding, requiring payment of more than 17.6 billion baht arising from the controversial 2007 sale of Shin Corp, a telecoms firm founded by Thaksin, to Singapore's Temasek Holdings Pte.
However, the network said there had been no clear progress in enforcing the collection of the tax debt.
The group expressed concern that if the matter drags on until mid-2027 -- the deadline for tax enforcement under Section 12 of the Revenue Code -- the state could lose a substantial revenue stream from the assets.
The network called on the prime minister to order relevant agencies to urgently enforce the ruling, saying only about 50 million baht had so far been recovered, a figure it described as extremely small compared with the total outstanding amount.