The bloodless revolution on June 24, 1932 was a turning point for modern Thailand, marking the moment the king’s absolute powers were replaced with a constitutional monarchy.

In recent years small groups of democracy activists have gathered each anniversary to lay flowers on a small bronze plaque marking the spot where the king was informed his absolute powers were no more.

The 30-inch plaque had rested in the floor of Bangkok’s Royal Plaza for decades.

But in April, it went missing, fuelling fears that officials were trying to whitewash history.

Police confirmed they would not tolerate any attempt to gather at spot on this year’s anniversary on Saturday week.

“This year we will not allow activists to come to lay flowers at the Royal Plaza because this is palace ground and it violates the NCPO (junta) order banning gatherings for political purposes,” Major General Phanurat Lukboon, deputy Metropolitan Police commissioner, told AFP.