Bangkok deputy governor Sakoltee Phattiyakul has confirmed his intention to run for city governor at the election expected in June.
Mr Sakoltee said he will formally announce his decision once the election date and timelines are announced by the government.
"I have been working [for the people of Bangkok] and I and my policies should be a choice for Bangkok voters, more or less," he said in an interview with Matichon on Friday.
The date for the Bangkok city election has not been set, but Prime Minister Prayut Chan-o-cha has said it may be in June.
The deputy governor did not say whether he would run as an independent or a party candidate.
He would be up against former transport minister Chadchart Sittipun, who is standing as an independent, Suchatvee Suwansawat, representing the Democrat Party, and former senator Rosana Tositrakul, also an independent candidate.
Mr Chadchart has been leading all opinion surveys, including the monthly Nida poll by the National Institute of Development Administration, as the voters' favourite. Mr Suchatvee was second in the Nida poll.
Bangkok Governor Pol Gen Aswin Kwanmuang, an appointee to the position, has not announced whether he will stand for election. The ruling Palang Pracharath Party remains noncommittal on whether it would support him.