Sunday's Provincial Administrative Organisation (PAO) elections will be fiercely contested with former allies pitted against one another in some key constituencies.
A feature of the PAO poll is that a province is counted as one constituency, unlike the general election where several constituencies cover one province.
The election will be held for 76 PAOs, each looking for a chairman and PAO member seats to fill. It is the first time a local election has been organised since the 2014 coup-makers suspended them to prevent political disturbances.
Political experts said the polls will be closely watched with the Progressive Movement fielding candidates. The group -- which promises to revolutionise the way PAOs are run with the use of technology and greater accountability -- is wooing young voters who it considers are agents of change.
Many PAOs are dominated by powerful political families. The movement is expected to add zest to the contest, but it is still thought to have a limited reach in locally and may only capture a couple of PAO chairman posts at best.
The group is vying for PAO chairman and contesting member seats in 42 provinces.
Weerasak Krueathep, a political scientist at Chulalongkorn University, told the Bangkok Post the PAO election will usher in no radical changes.
"The old faces are likely to return while the fresh-faced challengers will have a dim chance of victory. Their poll manifestos are not making an impact on voters," he said.
The last lap of the campaign has seen a build-up of political pressure not so much on the candidates, but groups and parties they represent in some provinces.
In Chiang Mai, an intensifying conflict between the main opposition Pheu Thai Party and Jatuporn Promphan, chairman of the red-shirt United Front for Democracy against Dictatorship (UDD), is turning the heat up in the PAO election there.
Mr Jatuporn opened his attack on Pheu Thai for allegedly dropping Boonlert Buranupakorn as its PAO chairman candidate in favour of Pichai Lertpongadisorn, a former senator.
The fallout caught many politicians in the opposition party and members of the red-shirt movement off guard as Pheu Thai and the UDD have always been strong allies.
Mr Jatuporn alleged the party falsely accused Mr Boonlert of showing a tendency to side with the rival ruling Palang Pracharath Party. He added a leading figure in the party had a free hand in unfairly picking Mr Pichai over Mr Boonlert.
The figure was thought to be a reference to Yaowapa Wongsawat, wife of a former prime minister, Somchai Wongsawat, and the sister of two others, Thaksin and Yingluck Shinawatra.
The UDD chairman described the accusation against Mr Boonlert as baseless. Mr Jatuporn said he had fought side-by-side with Mr Boonlert in a campaign to encourage voters to reject the constitution, drafted by an assembly appointed by the coup-maker, the National Council for Peace and Order, before it was put to a referendum in August 2016.
Mr Boonlert and his niece Thassanee Buranupakorn, the then Pheu Thai MP, were arrested on a charge of incitement in connection with the campaign. They were both detained on a military base under the "attitude adjustment" scheme.
Mr Boonlert will contest the poll as leader of the Chiang Mai Khunnatham group.
Mr Jatuporn said Thaksin has also been rallying behind Mr Pichai. The former premier has written a letter, tweeted messages and spoken in video clips vouching for Mr Pichai, saying the candidate has visited him in Dubai where Thaksin has been living in self-imposed exile.
In his message, Thaksin told Chiang Mai supporters Mr Pichai was the only person who understood how to make the province prosperous.
However, Mr Jatuporn said voters may be less attached to Pheu Thai and that Mr Pichai's chance of winning may be slipping away.
Mr Boonlert, on the other hand, has served three times as Chiang Mai PAO chairman and twice as Chiang Mai municipal mayor. He has worked for locals for years and is approachable.
In the South, the PAO poll in Phatthalung is expected to be a two-horse race between two politicians with past and present links to the Democrat Party.
Wisut Thampet, a former Phatthalung PAO chief, is seeking re-election. He is up against Phuchong Worasri, a former Phatthalung provincial council chairman who previously worked under Mr Wisut's PAO team.
Mr Wisut, who leads the Phalang Phatthalung (Phatthalung's Power) group, is known to be supported by Nipit Intharasombat, the former Democrat MP.
Mr Phuchong, meanwhile, broke away from the Democrat alliance and is competing in the Sunday PAO poll with the backing of the Bhumjaithai, also a coalition party whose candidate defeated Mr Nipit in last year's general election.
Mr Phuchong heads the Phumjai Phatthalung (Pride of Phatthalung) group.
A similarly close election has been predicted in neighbouring Songkhla where Palang Pracharath and the Democrats are vying for the PAO chairman seat.
Palang Pracharath rallies behind Col Suchart Chantharachotikul, of the Team Songkhla group. He is up against Sub-Lt Paijen Maksuwan, of the Team Democrat.
Col Suchart is believed to be leading the race, having hit the PAO poll campaign long before his rival candidate who started canvassing only three months ago.
Col Suchart previously directed Palang Pracharath's southern poll office credited with having won for the ruling party 13 MPs from the southern region.
However, Sub-Lt Paijen receives solid support from two of the Democrats' ministers: Deputy Interior Minister Niphon Bunyamanee and Deputy Transport Minister Thaworn Senneam.
But analysts said Palang Pracharath and Prime Minister Prayut Chan-o-cha have enjoyed a surge in popularity thanks to the much-touted "Kon La Kreung" 50-50 co-payment scheme and that could help boost Col Suchart's chances in the Sunday poll.
In the eastern province of Chon Buri, Witthaya Khunplome is seeking re-election as PAO chairman.
The Khunplomes have long been seen as a political dynasty in the province having long-dominated local politics. Mr Witthaya had served five times as an MP of the now-defunct Chart Thai Party.
He is challenged by Progressive Movement's candidate, Ploylapat Singtothong, whose Plien Chon Buri (Changing Chon Buri) team has pledged to break the political "monopoly" of the old guard, a reference to the Khunplome family.
In the Northeast, the PAO contest in Ubon Ratchathani is split three ways with candidates from Palang Pracharath, Pheu Thai and the Democrats campaigning hard.
The chances of Palang Pracharath's Cherdsak Pokkakulka of winning look promising as party members have assisted him on the campaign trail.