The Thai Raksa Chart opposition party said in a statement on Saturday that it would comply with the king's order invalidating Princess Ubolratana's candidacy for prime minister.
The party thanked the 67-year-old princess for her efforts, and said it would abide by election regulations and "tradition and royal customs" under Thailand's constitutional monarchy.
Thai Raksa Chart shocked the country when it announced Ubolratana as its candidate on Friday morning. Later that day, reigning King Maha Vajiralongkorn, 66, condemned the bid as unconstitutional and "inappropriate."
In a strongly worded statement, the king said senior royal family members should remain above politics and be politically neutral.
The Election Commission, which is overseeing the March elections, said it would issue a ruling on the issue on Monday. While the body has the final say on the list of candidates, it is unlikely to ignore the king's position in making its decision.
Battle between military and Thaksin loyalists
The upcoming general election — the first since a coup in 2014 — is widely seen as a contest between the junta and those, including Thai Raksa Chart, who are loyal to ex-premier Thaksin Shinawatra.
Ubolratana's candidacy would have pitted her against Prime Minister Prayuth Chan-ocha, who led the 2014 coup against a pro-Thaksin government.
The princess did not respond directly to her younger brother's efforts to cancel her bid. However, she thanked her followers on Instagram early Saturday and said she wanted Thailand to "move forward."
nm/aw (AFP, AP, dpa)