At least 600 police officers were deployed outside the court on Thursday ahead of the much-anticipated ruling, and the authorities slapped a ban on public gatherings within 50 metres of the building.
The decision comes amid fears that the Thai election, the first since a military coup in 2014, will be neither free nor fair as army chiefs seek to cling to power.
The poll will see a battle between democratic opposition parties, some of which are linked to Mr Shinawatra, and Phalang Pracharat, a party founded by military junta leader and prime ministerial hopeful, Prayuth Chan-o-cha.
Ahead of Thursday’s court drama, Preechapol Pongpanich, the TRC’s leader said that Thai Raksa Chart would accept the ruling and urged everyone to do the same.
“Today is an important day for our party. It will decide our future, whether we can continue on our path,” he said, urging party supporters to stay at home out of fear of unrest.