
On Monday, he has already signed a letter urging the Office of Attorney General (OAG) to ask the Civil Court to void the purchase contract or at least prevent the payment of the next instalment temporarily via an injunction.
Sukhumbhand has based his decision on the National Anti-Corruption Commission (NACC) conclusion that the purchase is mired in corruption.
"Looking into the ruling, I believe there is no other choice but to bring this case to the court," Sukhumbhand said Tuesday.
He also announced that he was ready to accept the consequences of his action.
"I have to do this even though I may end up being bankrupt," he said, "I can't just stay on and do nothing".
Sukhumbhand's predecessor, Apirak Kosayodhin, resigned shortly after being re-elected as Bangkok governor because NACC recommended legal action against him for his role in the fire-vehicle scandal.
The fire-vehicle deal was prepared at the time Samak Sundaravej was a Bangkok governor. While serving as the caretaker governor, Samak inked the purchase contract.
When Apirak succeeded Samak, he was very reluctant to go ahead with the purchase and asked for opinions from various authorities.
After being pressured by then-interior minister Bhokin Bhalakula, Apirak later opened the letter of credit allowing the purchase contract to take effect.
Apirak was blamed for not annulling the contract outright.