Former prime minister Benazir Bhutto said she would return to Pakistan today to end eight years of self-exile and lead her party into national elections despite threats of Al Qaeda inspired suicide attacks.

'Many threats have been made from left, right and centre to try and intimidate not only me, but most important of all, the people of Pakistan so that they should not go to the airport to receive me,' Bhutto said in Dubai.

Some 20,000 government security personnel were being deployed along the route from Karachi's airport to the site near the tomb of Pakistan's founder Mohammad Ali Jinnah where Bhutto planned to address a rally, according to a provincial official.

'There are intelligence reports that three different groups have plans to carry out attacks on Bhutto,' Ghulam Mohammad Mohtaram, Home Secretary of Sindh province, said.

The official said the suicide attacks were being planned by Pakistani jihadi groups linked to Al Qaeda and Pakistani Taliban commander Baitullah Mehsud, whose fighters were holding more than 200 Pakistani soldiers hostage close to the Afghan border.

Pakistan's biggest city was gearing up for her arrival.

Billboards bearing images of Bhutto smiling beneath a trademark white scarf loomed over downtown Karachi, while youths on motorcycles zipped through suburbs with pennants of her Pakistan People's Party (PPP) aloft.

PPP leaders predicted a million people will turn out to greet her, as supporters carrying red, black and green party banners streamed in from villages in the flat, arid hinterland of Sindh.

Despite being out of power since 1996, the charismatic Bhutto, 54, remains one of the most recognisable women politicians in the world, having been prime minister twice and the first female leader of a Muslim nation.

The US is believed to have quietly encouraged an alliance between President Pervez Musharraf and Bhutto to keep Pakistan pro-Western, committed to fighting Al Qaeda and supportive of Nato's efforts to stabilise Afghanistan.

But the timing of Bhutto's return is awkward for General Musharraf, who sees her as both a rival and potential ally after a general election due in early January.

Bhutto has ignored Musharraf's requests to delay her return, and on Wednesday spoke of their need to fight militancy together.

Flanked by her two daughters and her husband, Asif Ali Zardari, Bhutto said 'the unity of our country is at stake'.

The Bhutto family history has been closely entwined with Pakistan's torrid past.

Her father, Zulfikar Ali Bhutto, Pakistan's first popularly elected prime minister, was overthrown and hanged, while her two brothers were killed in mysterious circumstances, one gunned down in Karachi, the other found dead in a French Riviera hotel.

She first came to power after military dictator Mohammad Zia-ul-Haq, the general who ousted her father, was killed in a plane crash in 1988. Both her governments were brought down amid allegations of corruption and ineptitude.
 
Rapprochement with Musharraf, a general who came to power in a coup eight years ago, could lose Bhutto support at the polls.

Musharraf's popularity has plummeted this year, and the Supreme Court plans to hear challenges against the amnesty he has granted Bhutto to protect her from old corruption charges.

On Wednesday, the court reconvened a hearing on challenges to Musharraf's right to have stood for re-election while still army chief in a vote he won easily on Oct 6.

Proceedings will resume on Thursday.

Musharraf had said he would step down as army chief if re-elected, but there is speculation he might invoke emergency powers or martial law if the court blocks him.

Supporters of Nawaz Sharif -- the prime minister Musharraf ousted, exiled, and deported again when he tried to come back in September -- were given encouragement at another hearing.