Monday officially marked the start of the selection of new senators, a process that has become part of the ongoing war between progressive forces hoping for democratic political reforms and conservatives seeking to keep the status quo.

Hopeful candidates headed to district offices across the country on the first day of registration to compete for one of the 200 seats in Parliament’s upper house.

The power of the Senate — although limited compared to the House of Representatives, which has law-making responsibilities — was shown dramatically when it blocked the progressive party that won the most seats in from forming a new government.

The senators were able to do so because of the 2017 Constitution, adopted under a military government, which requires the prime minister to be approved by a joint vote of the elected House and the Senate, which was appointed by the military regime.

The Move Forward Party was opposed by senators who disapproved of its promise to seek reforms of Thailand’s monarchy.

The process of selecting the new senators will involve three rounds of voting: district, provincial and national.

Unlike the elected lower house legislators, the senators will be chosen by their fellow applicants, competing in 20 categories such as occupation or social position, including women, the elderly and the disabled.

The final results are expected to be released in July.

Critics say that the selection process outlined in the Constitution is so convoluted and ambiguous that it was intentionally designed to discourage public participation.

Critics also say that the Constitution allows the state bureaucracy to hold more power than directly elected political officeholders.

The new senators will no longer be able to take part in selecting a prime minister but will retain the power to approve legislation adopted by the House.

They also have the power to select members of supposedly independent regulatory bodies such as the Election Commission and the Constitutional Court, whose work has been widely seen as obstructing efforts at political reform and debilitating proponents with legal punishments, including prison.

The Senate’s votes are also needed to amend the Constitution. The governing Pheu Thai party is pushing for a new charter to replace the 2017 one to facilitate certain reform efforts pledged during the campaign.

Civil society groups have campaigned to increase public awareness and encourage those supporting democratic reforms to enter the Senate selection process.

Yingcheep Atchanont, a law reform advocate with the group iLaw, has been organizing public discussions on the importance of the Senate and workshops to help potential applicants understand how the selection process works.

“We are informing people what to do if they want change. There have been calls in recent years to reduce the power of the Senate, to get rid of the Senate,” he said. “All of this can only happen if we can amend the Constitution, and we need from the senators for that.”

Candidates must be over 40 years old and have more than 10 years of experience in their chosen occupational group, a provision that does not apply to those competing in one of the social identity groups. They also cannot campaign or do anything that can be perceived as campaigning.

Even the Election Commission has admitted that the process is complicated but says it will be able to carry it out smoothly and transparently.

Purawich Watanasukh, a political science lecturer at Bangkok’s Thammasat University, said he believes the complicated rules were deliberately designed to discourage public participation.

“This is the fight of the people to debug not only the Senate itself, but the Constitution, which would lead to a new political landscape in Thailand,” he said, “”It will be the next battleground between the progressive movement and the establishment.”