Anudit Nakornthap will join the Thai Sang Thai Party (TST) and serve as its anti-graft director, the party says.
The party will introduce Mr Anudit as a member on Tuesday at the opening of the party's new anti-graft office on Soi Sukkhonthasawas 17.
Mr Anudit's joining the TST comes after the party put up roadside billboards declaring a campaign policy that will focus on combating corruption.
The catchphrase of the party's anti-graft platform is "Combat Corruption With Us".
The campaign began with rumours that the former Pheu Thai Party MP would take up the post of the TST's anti-graft director.
Mr Anudit has been active in running a community service webpage called Sai Mai Tong Rod (Sai Mai Will Survive), which was credited with assisting people facing hardship during the Covid-19 crisis.
He was a former Information and Communication Technology Minister during the Yingluck Shinawatra administration and once served as Pheu Thai's secretary general.
He resigned from the party and his position as MP for Bangkok's Sai Mai district on Friday, according to an earlier report.
In a resignation statement made at Pheu Thai's headquarters, Mr Anudit praised his father, Thiti Nakornthap, a former secretary-general of the dissolved Samakkhee Tham Party, for his 16-year political journey.
He also gave credit to Khunying Sudarat Keyuraphan, the TST leader to whom he has retained close political ties.