Najib lost power in 2018 when his party, which had governed the Southeast Asian nation for six decades, was defeated at the polls after he became embroiled in a financial scandal.
The leader and his cronies were accused of stealing billions of dollars from state investment fund 1MDB, and he has since been convicted and sentenced to 12 years in jail in the first of several trials he is facing over the fraud.
Last year, a court ordered Najib — who remains free on bail and is still an MP — to pay 1.69 billion ringgit ($409 million) in taxes owed between 2011 and 2017.
Late Tuesday, Najib said that tax officials issued a notice demanding he settle the bill, plus additional costs, otherwise they will launch bankruptcy proceedings.
If he is declared bankrupt, the ex-premier will lose his seat in parliament and be barred from standing in elections.
The 67-year-old insisted he had always paid his taxes, and that the case against him is politically motivated.
“I will continue to stand up and fight against every attempt to bully and intimidate me by those in power,” he wrote on Facebook, adding he had asked his lawyers to try to get the proceedings halted.
The tax office declined to comment.
The prospect of bankruptcy comes as different factions battle for control of Najib’s party, the United Malays National Org ..