Deputy Interior Minister Chada Thaiset issued a warning against obstructing royal motorcades, saying such actions would be met with severe consequences in the future.

"It is unacceptable and extremely inappropriate," the minister of the Bhumjaithai Party said. "I won't let it happen again."

Mr Chada referred to the incident around 6.20pm on Sunday when a car honked at the convoy of Her Royal Highness Princess Maha Chakri Sirindhorn on an expressway in Bangkok.

A passenger in the front seat of the car was Tantawan “Tawan” Tuatulanon, a 21-year-old political activist charged with lese majeste for running an opinion poll on royal motorcades.

Video clips on social media showed Ms Tawan in an argument with a police officer, questioning the preferential treatment given to certain vehicles.

Princess Sirindhorn is a regular visitor to Uthai Thani, where she has a residence next to the house of a close friend since their time at Chulalongkorn University.

The princess asked the province not to close a road in front of her house, not wanting to inconvenience the public, Chada said.