Mongolian prime minister Luvsannamsrain Oyun-Erdene has resigned after losing a confidence vote in parliament.

The vote followed days of mass protests over corruption allegations – fuelled by social media posts about his son’s lavish birthday party and engagement.

Oyun-Erdene, who took office in 2021, will remain as caretaker PM until a successor is appointed within 30 days.

“It was an honour to serve my country and people in times of difficulties, including pandemics, wars, and tariffs,” he said after the vote.

He had to stand down as he fell short of a majority, or 64 of the 126-seat parliament. Some 82 lawmakers took part in the secret ballot, 44 of whom voted for Oyun-Erdene, while 38 voted against him.

Hundreds of protesters, many of them young people, had been taking to the streets for two weeks before the vote, demanding Oyun-Erdene’s resignation.

In particular, they pointed to his family’s – especially his son’s – apparent lavish lifestyle, questioning the source of their wealth.

Mongolians have circulated on social media an extravagant wedding proposal by Oyun-Erdene’s son, as well as expensive fashion items.

Oyun-Erdene has rejected allegations of corruption, accusing critics of launching a smear campaign against him.

According to Transparency International, a watchdog, Mongolia has seen worsening corruption since Oyun-Erdene came into power. Last year, it was ranked 114th out of 180 countries in terms of government transparency.

A former communist state sanwiched between Russia and China, Mongolia has been transitioning to democracy since the fall of the Soviet Union in the early 1990s.

Corruption is a persistent problem. Last year, US prosecutors sought to forfeit former Mongolian PM Sukhbaatar Batbold’s two New York apartments that he allegedly bought using stolen mining funds.

Batbold, who served from 2012 to 2015, denied wrongdoing.

In recent years, Mongolia has sought to build closer ties with the West, counting the United States and European countries as part of its “third neighbour” foreign policy.