A group of 30 activists calling themselves Prachachon Khonthai (People of Thailand) says it will file a petition to disband the ruling Palang Pracharath Party next week.
The demonstrators gathered on Phitsanulok Road in Bangkok on Saturday afternoon amid a security presence of around 300 policemen.
Leader Nititorn Lamlua, a former People's Democratic Reform Committee activist, said his group also wanted Prime Minister Prayut Chan-o-cha to resign for failing to solve economic problems.
It also sought to nullify the results of the 2019 election, viewing the calculation of list MPs, especially by adding fractions, might be unconstitutional.
The rally disbanded at 6pm. Another anti-government group, led by former red shirt leader Jatuporn Prompan and sharing a similar agenda, gathered at the same spot later.