To Lam takes his oath as Vietnam's President during the National Assembly's summer session in Hanoi on May 22, 2024. [AFP]

Vietnam's rubber-stamp parliament voted in public security minister To Lam as the country's new president on Wednesday, after a major anti-corruption campaign forced his predecessor to resign.

Thousands of people -- including several senior government and business leaders have been caught up in the Southeast Asian country's "blazing furnace" crackdown on graft, led by Communist Party General Secretary Nguyen Phu Trong.

Analysts have said that Lam, who is deputy head of the steering committee on anti-corruption, has weaponised its investigations to take down his political rivals.

In his first remarks as president, Lam said he was "determined to fight corruption and negative phenomena".

Lam takes over from Vo Van Thuong, who resigned in March over what the party called "violations and shortcomings", after just a year in the job.

Led by the Communist Party general secretary, Vietnam has a four-person leadership structure that also includes the president, prime minister and head of the National Assembly.

The National Assembly chairman also resigned in April over "violations and shortcomings", meaning two of the country's top four positions had been vacant for a month.

Lam, 66, has been public security minister since 2016 and has taken a hard line on human rights movements in the communist country.

It had appeared he was set to hold the presidency and his position at the Ministry of Public Security (MPS) concurrently, which would have been a first for Vietnam.

But hours before the secret ballot, parliamentarians agreed they would relieve him of the powerful role.

"The indecision on the MPS post shows that other elite members are hesitant to grant the MPS to any of To Lam's proteges," Nguyen Khac Giang, visiting fellow at the ISEAS – Yusof Ishak Institute, told AFP.

"And To Lam himself is reluctant to relinquish control over the main executioner of the anti-corruption campaign," he said.

The National Assembly elects the president by secret ballot, with deputies then approving the results.

Lam carried 472 of 473 votes.

On Monday, Tran Thanh Man, 61 was nominated as the new head of the National Assembly, and the party has appointed four new politburo members.

Political upheaval is uncommon in Vietnam, and for years all changes were carefully managed with an emphasis on cautious stability.

In the past 18 months, Vietnam also saw the resignations of the deputy prime minister and the head of the party's economic commission, while its once 18-strong parliament briefly fell to 12 members.

Former president Vo Van Thuong's predecessor, Nguyen Xuan Phuc, also resigned during that window.

Steaks and noodle soup

Lam has spent his whole career within the secretive MPS, which deals with the monitoring of dissent and surveillance of activists in the authoritarian state.

Rights groups say the government has in recent years stepped up a crackdown on civil society groups.

Two hundred activists are currently in prison, according to Vietnam-focused human rights organisation The 88 Project.

Three years ago, he was at the centre of a scandal that sparked online anger in Vietnam when he was filmed eating steak smothered in gold leaf at a London restaurant -- shortly after laying a wreath at the grave of Karl Marx.

The restaurant, Nusr-Et Steakhouse, named after Turkish chef Nusret Gokce -- known to his nearly 40 million Instagram followers as Salt Bae -- serves up steaks wrapped in edible 24-carat gold leaf, reportedly costing more than $1,000.

The average person in Vietnam earns a few dollars a day.

Months later, Vietnam jailed a noodle seller who had posted a parody video that went viral, in which he impersonated Salt Bae by sprinkling herbs on noodle soup, calling himself "Green Onion Bae".