Asked by journalists whether he would stand down, Prayuth simply said "won't quit" after Buddhist prayers that were held to call for national healing following months of protests that have also demanded reforms of the monarchy.

After the deadline expired, one group of protesters said they would protest on Sunday.

Another group said they would go to the German embassy on Monday - making an indirect reference to the fact that the king spends much of his time in Germany.

"Prayuth is the problem. The first obstacle that we need to remove," said Jatupat "Pai" Boonpattararaksa, one of the leaders of the demonstration planned for Sunday.

He was among dozens of protesters arrested this month and was freed on bail on Friday.

Since July, protesters have been demanding the departure of Prayuth and a new constitution. More recently they have also stepped up demands for reforms to curb the powers of King Maha Vajiralongkorn's monarchy.

Prayuth, who first took power in a 2014 coup, rejects the accusations of his critics that he engineered last year's election to keep power.

After the prayers he said: "I urge everyone to conciliate and help solve problems together."

He has called for an emergency session of parliament on Monday and Tuesday to try to resolve the crisis, but his opponents have little faith in the outcome given his supporters have a parliamentary majority.

The king has made no public comment on the protests but his praise on Friday for a man who held up a royal portrait at an anti-establishment rally stirred passions - with monarchists lauding the action and protesters pouring scorn.

Australian Associated Press