The announcement by the Sri Lanka Muslim Congress on Sunday will be a major blow to Rajapaksa’s campaign for a third term in office with more than 20 lawmakers and ministers defecting to the opposition.
Ameer Faaiz, a leader of the party that represents minority Muslims in overwhelmingly Buddhist Sri Lanka, cited the Rajapaksa administration’s “intolerance toward religious minorities” and disagreement with his style of rule.
He said the party consulted its supporters who were of the overwhelming opinion that they could no longer stand with Rajapaksa and would throw their support behind his rival Maithripala Sirisena.
An attack on Muslims in June by Buddhists that left three dead and dozens injured exacerbated ethnic tensions in the aftermath of a decades-long civil war against Tamil Tiger rebels that ended in 2009.
Rajapaksa’s government had come under heavy criticism in recent years for backing extremist Buddhist groups and turning a blind eye to the recent anti-Muslim violence.
Sirisena is a former health minister who split from Rajapaksa last month to run for president in the biggest challenge for the incumbent since his first election in 2005.