By Charles Haviland BBC News, Colombo

Buddhist monks have been calling on the President Mahinda Rajapaksa to release Mr Fonseka

Ten days ago it got worse for the former general Sarath Fonseka as he began a 30 month jail sentence in one of Colombo’s most notorious prisons for using nepotism in purchasing military supplies.

And this week the authorities declared that he has lost his parliamentary seat.

The opposition disputes the legality of that ruling and is resuming protests in his favour.

Presidential pardon

Prison officials say that Sarath Fonseka is afforded some extra security in the Welikada jail, which also holds suspected Tamil Tiger militants.

	Sri Lanka's opposition is largely weak and divided; recently some MPs defected to government

In the past few days senior ministers have been heavily hinting that he might get a presidential pardon, but only if he himself pleads for one.

His wife says he would not do that as he is not guilty of anything.

Some of the opposition parties which fielded him as their candidate in January have resumed campaigns to get him freed.

But the street demonstrations often have difficulty attracting large crowds, despite Mr Fonseka’s undoubted popularity among many people.

He is not a figure that many human rights groups, whether local or foreign, want to espouse; his own reputation from the war years is too controversial for that.

At the same time, his absence from the political scene, including, now, from parliament, has more or less silenced the most outspoken and witheringly anti-government political voice in Sri Lanka.

That is in a context where the opposition is largely weak and divided, and has recently seen many of its own numbers enticed to defect to the government side for voting purposes.

Should any pardon be granted, there would still be big question marks about Sarath Fonseka's future as there is still a series of charges pending against him.

The government has been especially angry ever since Mr Fonseka was quoted as implying that the defence secretary might have been a party to war crimes.