By Penny Dale BBC, Lusaka

Zambia's ruling Movement for Multi-party Democracy (MMD) has scored an important victory by holding on to their parliamentary seat in rural Keembe, about 100km north of Lusaka.

No official results have yet been released, but Anderson Mazoka's United Party for National Development (UPND) has conceded defeat, even though it accuses the MMD of buying votes with beer and maize.

Estimates from the ground indicate a MMD win with a resounding 70% of the vote.

Mr Mazoka wants the election vote overturned

The MMD's success gives a beleaguered President Levy Mwanawasa a much-needed boost and hands his party a slim majority in parliament.

The MMD now has one more seat than the opposition - enough, providing no one breaks ranks, to pass ordinary legislation but not enough to make changes to the constitution.

As well as smarting from the by-election loss, Mr Mazoka also has to face what is likely to be a tough audience with the Supreme Court next week.

Contempt of court?

Mr Mazoka along with General Christon Tembo and General Godfrey Miyanda wanted to overturn President Levy Mwanawasa's election.

Mr Mazoka made this the focus of a rally speech in the campaign to win the crucial by-election, held on Thursday in Keembe.

Vice-President Enock Kavindele also succumbed to temptation.

Mr Mwanawasa officially got 29% of the vote in 2001

But the pair may have to pay a high price for their loose tongues: the Supreme Court has summoned both to appear before it on Tuesday next week to tell the court why they should not be cited for contempt of court.

The court is obviously fed up that despite numerous warnings politicians have continued to make political capital out of the ongoing presidential election petition.

They will have to try to convince the judges that their recent comments on the evidence of former head of intelligence Xavier Chungu do not amount to contempt of court and have not scuppered the chances of a fair outcome.

Mr Kavindele has said that Mr Chungu's claim that the MMD used government money in the 2001 elections is untrue.

Mr Mazoka has said that Mr Mwanawasa should step down on the basis of Mr Chungu's evidence.

If found to be in contempt of court, the pair could face a spell in prison.