Lahore, Jan 19 (IANS) With Pakistani President Asif Ali Zardari facing the prospect of being jailed after the corruption cases against him are reopened, a petition has been filed in the Lahore registry of the Supreme Court seeking constitutional indemnity from prosecution for his office.

Barrister Zafarullah of the little-known Watan Party said in his petition filed Monday that the president, under Article 242 of the constitution, could not be summoned to any court of the law as he is the head of the state.

It said a Supreme Court order on reopening corruption cases against some 250 politicians, bureaucrats and retired military officers who had benefited from a graft amnesty that the court has invalidated did not apply to Zardari as he was the president.

Zardari has been on tenterhooks since the Supreme Court last month invalidated the National Reconciliation Ordinance (NRO) that had enabled him and his slain wife, former prime minister Benazir Bhutto to return home from self exile.

Then president Pervez Musharraf had promulgated the NRO in October 2007.

Zardari is on an extremely sticky wicket as the Supreme Court itself will have to rule on whether or not he enjoys constitutional immunity from prosecution.

And, given the court's judicial activism since last July, when it first declared the Nov 3, 2007 emergency Musharraf had imposed as unconstitutional and then its order against the NRO, it is highly unlikely to oblige Zardari, analysts here.

On Monday, Online news agency had reported that Zardari had been advised to quit when it became known that the Supreme Court would strike down the NRO.

Sources close to presidency told Online that the president had taunted the individual who had given the advice, saying: 'I don't care if the decision is against or in favour of me. I will face the challenges. I am habitual of it'.