Sri Lanka's parliament on Wednesday voted out the bitterly disputed government of former strongman Mahinda Rajapakse, removing one controversial figure but leaving the country in a power vacuum.

The island nation has been in crisis since the president sacked prime minister Ranil Wickremesinghe on October 26 and replaced him with Mr Rajapakse, who served as president until being voted out three years ago.

On Tuesday the Supreme Court overruled the president's dissolution of parliament and halted preparations for a snap election, in a major boost for the ousted prime minister.

In stormy scenes Wednesday, legislators gave their verdict on the two rivals - with a majority in the 225-member assembly supporting a no-confidence motion against Mr Rajapakse.

Parliament also passed motions declaring illegal the November 9 proclamations made by Maithripala Sirisena, the president, to enshrine the power shift.

The result however does not automatically mean that Mr Wickremesinghe, who has refused to leave the prime minister's residence, has won the constitutional showdown.

Day-to-day administration remains paralysed as the crisis drags on and there are growing fears for the economy and Sri Lanka's ability to repay its huge foreign debts.