The reason for their decision is not known.

Meanwhile, nearly 40 members of the ‘joint opposition’ formed by UPFA MPs are to vote against the budget.

Of the 96 SLFP MPs in parliament, 42 are either cabinet, state or deputy ministers.

Opposition MPs to govt.

Meanwhile, parliament sources say several UPFA MPs are to cross over to the government tomorrow.

On the instructions of prime minister Ranil Wickremesinghe, leader of the House Lakshman Kiriella has informed all government MPs that they should be present at the vote, and that they should be there by 3.00 pm.

Chief government whip Gayantha Karunatilake has informed them to vote in support of budget 2016.

Meanwhile, president Maithripala Sirisena is due to chair a special meeting of the SLFP at the parliamentary complex starting at 10.00 am tomorrow.