Metropolitan Police Bureau (MPB) chief Khamronwit Thoopkrachang will swap jobs with Suthep Detraksa, commander of the Provincial Police Region 5, in a move set to get the stamp of approval on Friday.
National police chief Pol Gen Adul Saengsingkaew on Thursday confirmed the transfer decision and denied that it was due to political pressure.
The switch was appropriate, he said.
This photo hangs in Pol Lt Gen Khamronwit's office, showing Thaksin pinning on his insignia in Hong Kong after he was promoted to city police chief. The inscription written by Thaksin congratulates.
The changes also include Pol Lt Gen Dr Jongjet Aojenpong, director of the Police General Hospital, who will be promoted to be an assistant police chief, replacing Pol Lt Gen Aekarat Meepreecha, who asked for early retirement because of health problems.
The reshuffle will be approved at a meeting set for Friday, Pol Geb Adul said.
News of the transfer of Pol Lt Gen Khamronwit, a staunch supporter of Thaksin Shinawatra, from head of the Metroplitan Police Bureau to the chief of the North Region, spread on Wednesday, before Pol Gen Adul acknowledged it.
Chalerm Yubamrung, director of the Centre for the Administration of Peace and Order (Capo) and the caretaker labour minister, said on Thursday he was ''shocked'' by the decision.
The outgoing MPB chief is close to Thaksin Shinawatra. His successor, Pol Lt Gen Suthep, has spent most of his police career in the northern region, the fugitive former premier's home country.
A police source said Pol Lt Gen Khamronwit's replacement also has close ties with the former prime minister. ''He is one who is trusted by Thaksin,'' the source said.
''Pol Lt Gen Suthep is also close to Pol Gen Priewpan Damapong,'' the source added.
''Both are fighters, although Pol Lt Gen Khamronwit is more aggressive,'' the source said.
Pol Lt Gen Khamronwit is a target of strong criticism by the People's Democratic Reform Committee for throwing full support behind caretaker Prime Minister Yingluck Shinawatra as city police chief.
Anti-government leaders have said in several occasions that the MPB chief is on the top list of their list of targets to pay the price for backing Ms Yingluck if they are successful in ousting the Pheu Thai Party-led caretaker administration.
The source said Pol Lt Gen Khamronwit had wanted to leave the city's top police post and had informed his boss of his plans.
Pol Lt Gen Khamronwit wanted to avoid further criticism during the new gubernatorial election in Bangkok. He was accused of taking sides with Pheu Thai candidate Pol Gen Pongsapat Pongchareon in the election on March 3, 2013.
Last month the Election Commission declared the election last year annulled after finding that the "winner", Sukhumbhand Paribatra of the Democrat Party, violated the Local Election Act during the campaign.
MR Sukhumbhand ceased duties as governor in March after the Appeals Court took up the case.
The source said Pol Lt Gen Khamronwit may enter politics after his retirement at the end of September, and could be setting his sights on his home province of Pathum Thani.
''He might want to spend the rest of his career before he retires in preparing to enter politics,'' the source added.