The Supreme Court in Sri Lanka has paved the way for a far-reaching constitutional amendment to go before parliament without a referendum.
The change would abolish limits on the number of presidential terms and hugely increase the president’s powers.
Opposition supporters have staged demonstrations against it in several parts of Colombo.
But the measure is almost certain to be passed by the chamber when it votes on the amendment on Wednesday.
Thousands joined opposition demonstrations against this controversial change, called the 18th Amendment.
There is heavy security around parliament
The government’s critics call it an “onslaught on democracy”.
But President Mahinda Rajapaksa says it will increase voters’ choice.
The amendment would lift restrictions on the number of presidential terms, currently two, letting Mr Rajapaksa stand again in 2016.
And it would boost his powers, letting him appoint all the top judges and commissioners for elections, human rights and other affairs, unfettered by any legal veto.
Chrishmal Warnasuriya, who led a group of protesting lawyers, said that the proposals were undemocratic.
“The people have not been consulted on the matter – we say refer it to the people, they have a right to be heard on the matter, it’s their constitutional right, give it to them by way of a referendum, and then if you still feel that the amendment should go through then the people will decide.”
But the government has induced a large number of opposition MPs to vote for it.
One of them, Rauff Hakeem of the Sri Lanka Muslim Congress, said he was uneasy at the way the bill was being rushed through as an “urgent measure”.
But he said that by supporting the measure he would secure development benefits for his community.
“That has been the practice in this country – where unless you are able to influence policy, just shouting from the rooftops, bringing pressure by simply shouting hoarse, is not going to bring relief to the people,” he said.
The main opposition party says it will boycott the vote entirely. So the government is all but certain to get the two-thirds majority it needs to pass the bill into law.
By Charles Haviland, BBC News, Colombo