Thousands of protesters have gathered in the Thai capital Bangkok, calling for the resignation of Prime Minister Paetongtarn Shinawatra after a phone call she had with the former Cambodian leader Hun Sen was leaked, BBC reported.

In the call, which was about a recent incident on their border, she addressed Hun Sen as "uncle" and said a Thai military commander handling the dispute "just wanted to look cool and said things that are not useful".

The call has sparked public anger and a key partner in her ruling coalition has quit. Paetongtarn apologised, but defended the call as a "negotiation technique".