The speaker announced that the members of parliament had voted unanimously to lift Mr Chiluba's immunity from prosecution.

MPs were under pressure to make a swift decision

The BBC's Penny Dale in Lusaka says the arrest of the former head of state is likely to be take place any day now.

She says Zambians will be happy with the decision and are expected to celebrate.

The debate was originally expected to take place on Wednesday, but the agriculture minister used a loophole in the law on Tuesday afternoon and the vice-president of parliament was able to put forward a motion to lift Mr Chiluba's immunity.

'Caged for life'

Thousands of Mr Chiluba's opponents demonstrated outside parliament in Lusaka earlier on Tuesday as MPs met to prepare the debate on lifting his immunity from prosecution.

Ordinary people, women's groups and anti-corruption campaigners chanted slogans and carried placards denouncing the former president and demanding a swift decision.

Outside the parliament building, a group of students carried a banner saying "Chiluba must be caged for life".

Frederick Chiluba has denied the allegations of corruption against him made by his successor, Levy Mwanawasa, in parliament last Thursday.

Mr Chiluba was believed to be staying in his secure Lusaka residence on Tuesday, with feelings running so high in the capital.

Our correspondent says the former head of state has not been able to move about freely because of the allegations made against him.

'Puppet' breaks free

The former president has protested his innocence and said he was the victim of a witch-hunt.

Addressing a press conference in Lusaka on Sunday, Mr Chiluba lamented: "Zambia is degenerating into an intolerant society where brother eats brother".

Mwanawasa asked MPs to end Chiluba's immunity

On Thursday, President Mwanawasa asked a special session of parliament to lift Mr Chiluba's immunity from prosecution and outlined a series of corruption allegations against him and members of his government.

Mr Mwanawasa was elected as president in December 2001 in a widely disputed election. His victory is being challenged by the opposition in the Supreme Court.

When he was first chosen to be the presidential candidate for the ruling Movement for Multi-party Democracy (MMD), Mr Mwanawasa was seen by many observers as "a puppet" of Mr Chiluba.

Since his election, he has made the fight against corruption a priority for his government.

This has had the effect of splitting the MMD into pro-Mwanawasa and pro-Chiluba camps.

The anti-corruption campaign has led to the resignation of the foreign minister and the arrest of the Zambian ambassador to Washington.