A royalist-supporting grandmother was mobbed when she gatecrashed a protest in Thailand on Friday night over the country's recent sham election.

The elderly woman in a white flowery dress and glasses interrupted the rally at Kasetsart University in Bangkok, with a sign reading 'We love our king'.

The supporters of the Move Forward party surrounded her while she was ushered away. It came at a demonstration against the junta's Communist-style move this week to ban the recent poll winner Pita Limjaroenrat from politics.

Military-controlled courts also ordered the former executive director of NASDAQ-listed ride-hailing app Grab to be suspended from politics while they investigate probate shares in an inactive media company held by his late father.

Much of the resistance to the political party has been around their plans to water down the power of the increasingly-disliked monarchy, which is protected by draconian Lese Majeste laws.

Harvard-educated Pita Limjaroenrat - the first ever Thai awarded a scholarship to the prestigious U.S. school - won the quasi-democratic vote on May 15 with 38 per cent of the total but was repeatedly blocked by the royalist establishment from becoming Prime Minster due to 'threats to national security' over his progressive manifesto.

However, moves to silence the leader of the hugely popular Move Forward party was launched when Pita vowed to stick to his pledge to scrap Lese Majeste laws and legalise criticism of Thailand's controversial monarchy, which is the richest royal family in the world following years of draining the public purse and widespread indoctrination of the populace.

Researchers claimed that in 2021, the Thai monarchy received a budget of 1.09 Billion USD - more than 10 times the amount received by the British Royal Family.