Dumeetha Luthra BBC Correspondent in Colombo

"We will withdraw from coalition" - JVP leaders

The People's Liberation Front, or JVP, have issued an ultimatum: either the government drops the plan by Wednesday, the 15th or they will withdraw from the coalition.

The protest comes as international donors once against underline their support for the agreement.

Protesters jammed the streets of the capital, Colombo. Shouting "down with the joint mechanism" they accused the president, Chandrika Kumaratunga, of dealing with what they called terrorists.

This is not the first and the last coalition. We will come forward with another. JVP MP Wimal Weerawansa

The aid deal has been hugely controversial. Violent demonstrations in the past few days highlight its unpopularity.
Designed to ensure proportional distribution of relief to all parts of the devastated island, it has become a political fiasco.

It has underlined and widened the divisions with the ruling coalition. The hardline nationalist Peoples Liberation Front, or JVP, is adamantly opposed to any deal with the Tamil Tiger rebels.

It's given the president until Wednesday, the 15th to renounce the mechanism otherwise it'll withdraw from the coalition.

However, analysts say the President's credibility is at stake -- she has to sign. This all comes amid a backdrop of a deadlocked peace process and increasing factional fighting and political killings.