"I'll never leave the SLFP," he told LBO.
Rajapaksa is chairman of the Committee on Public Enterprises (COPE) which has been probing allegations of corruption in state enterprises as well as allegedly fraudulent privatisation of state ventures.
The committee has issued reports giving details of alleged corruption and these are now being investigated by the attorney general who will decide on prosecutions.
The COPE report found fault with both ruling coalition as well as opposition law makers and also called for the reversal of certain privatisation agreements.
Rajapaksa had been pressing for more vigorous action against those accused in the COPE reports and had accused the government of trying to delay or evade investigations into the COPE findings.
His cross over will fuel