Supreme Court declared that the constitution can be amended by a vote in parliament, and a referendum is not needed to endorse the changes.

The amendment will concentrate more powers on the president

Ruling coalition had secured the required two-thirds majority in parliament with several opposition members pledging support for the amendments.

New changes will end the current two term limit on presidents.

Beyond 2016

Mahinda Rajapaksa won a second term in January but would have to step down in 2016 under the present constitution.

	The ruling was announced by the speaker

"The Supreme Court has said the Constitutional Reforms Bill does not require a referendum in order to be passed, instead it only requires a two-thirds majority in parliament," Speaker Chamal Rajapaksa, who is the president's elder brother, announced in parliament.

The draft bill will be debated and voted on by the 225 member parliament on Wednesday.

UNP walkout

The main opposition UNP staged a walkout from Parliament after UNP Leader Ranil Wickremesinghe gave a speech saying his party will not participate in the debate on the 18th Amendment.

Parliament sittings were suspended for 10 minutes following the walkout.

The UNP members began a Sathyagraha campaign outside Parliament.

The main Tamil Party, Tamil National Alliance (TNA) said on Monday that they will vote against the amendment.