Hundreds of Thai royalists in yellow shirts demonstrated outside parliament on Tuesday, calling on lawmakers to reject changes to the constitution drawn up by the country's former military junta in response to mounting anti-government protests.
Demonstrations were due to be held later by anti-government protesters, who are seeking the removal of Prime Minister Prayuth Chan-ocha, a former army ruler, and reforms to curb the powers of the monarchy.
"Amending the constitution is going to lead to the abolition of the monarchy," royalist leader Warong Dechgitvigrom told reporters at the demonstration, several hundred metres from the parliament building, which was encircled with police barricades built from concrete blocks and barbed wire.
Lawmakers are due to discuss several proposals for the way in which the constitution can be amended - some of which would exclude the possibility of changes to the way King Maha Vajiralongkorn's monarchy is treated under the constitution.
There is also discussion of the role of the Senate, which was entirely selected by Prayuth's former junta and helped ensure that he kept power with a parliamentary majority after a disputed election last year. Prayuth says the vote was fair.
Protests since July initially targeted Prayuth and constitutional change, but have since called for the monarch's role to be more clearly accountable under the constitution and for the reversal of changes that gave the current king personal control of the royal fortune and some army units.
"We don't want them to amend anything on the monarchy," said Samutprakan Chum, a 58-year-old royalist. "The monarchy is heavenly, we are down in hell, we are far beneath them, we have to know our place."