President Asif Ali Zardari, who was in Dubai for medical treatment, returned on Monday to Pakistan, where tension is rising between his civilian government and the military over a memo accusing the country's generals of plotting a coup.

It's not clear when the deeply unpopular leader who has uneasy ties with the army will return to work. He flew into the southern city of Karachi.

"The president is thankfully fit and healthy and that is why he has returned," Shazia Marri, information minister for Sindh province, of which Karachi is the capital, told Reuters.  "However, his activities over the next few days will depend on what the doctors advise."     

Zardari could be damaged by the memo, reportedly crafted by the former Pakistani ambassador to the United States, which wants ally Pakistan stable so it can help wind the war down in neighbouring Afghanistan. 

Businessman Mansoor Ijaz, in a column in the Financial Times on October 10, said a senior Pakistani diplomat had asked that a memo be delivered to the Pentagon with a plea for US help to stave off a coup in the days after Osama bin Laden was killed in Pakistan in a US raid, to the embarrassment and anger of the  military.

Ijaz later identified the diplomat as Husain Haqqani, the then Pakistani ambassador to Washington who is close to Zardari. Haqqani denied involvement in the memo but resigned over what has been dubbed "memogate".     

The Supreme Court on Monday started hearings into a petition demanding an inquiry into who was behind it. As president, Zardari is immune from prosecution but the controversy could seriously damage him politically. If a link is proven, the military, which has long been distrustful of Zardari, could push for his ouster.

Although Zardari has been a largely ceremonial president since constitutional amendments last year, he wields considerable influence as leader of the ruling party and his forced departure would be a humiliation for the civilian leadership and would throw the country into turmoil. - Reuters