Penuell Maduna, the embattled minister of justice, says that he will not be available to serve as a minister in President Thabo Mbeki's cabinet after next year's elections.

Maduna's statement, made during an exclusive interview, follows a series of allegations against him that range from spying for the apartheid regime to nepotism and corruption in his department.

Maduna acknowledged that the African National Congress had been torn apart by allegations that Bulelani Ngcuka, the national director of public prosecutions, had been an apartheid spy.

"The ANC is hurting badly," he said.

"But I don't care anymore what this is doing. It has already done a lot of damage. Families are suffering.

"They can't take it any longer. I will serve in the ANC in any other capacity, even as a floor sweeper."

Asked whether he was set to quit his ministerial post now, Maduna said: "No, I am not quitting. I will serve my full term but I will not stand again."

Maduna's extraordinary pledge could make him the first victim of the escalating political row sparked by the Scorpions' investigation into whether Deputy President Jacob Zuma solicited a R500 000 bribe from a French arms company bidding in the multibillion-rand arms deal.

The row reached new heights when ANC veteran Mac Maharaj supported claims that Ngcuka, the Scorpions' chief, was an apartheid spy.

This week a judicial commission, appointed by Mbeki and headed by Judge Joos Hefer, extended its mandate to include an investigation of Maduna as the minister with line responsibility for Ngcuka's national prosecuting authority.

In an interview held at a Cape Town hotel, Maduna told of his anguish and frustration following accusations from mining magnate Brett Kebble that he had abused his office as the minister responsible for the national director of public prosecutions; claims by a senior official in his department that he was guilty of nepotism and corruption in the liquidation section; and continuing charges by Patricia de Lille, the leader of the Independent Democrats, that he was on a list of ANC apartheid spies.

Maduna, clearly at the end of his tether with the barrage of allegations made against him in recent weeks, said he had promised his family that he would quit his high-profile position.

"I told the president my family is saying I should resign because they cannot take it any longer," Maduna said.

"Just this morning one of my brothers-in-law, Sandile Mshengu, phoned me and said all my in-laws would be very happy if this noise stopped. I repeated the promise to him."

Maduna said he would serve his full term until the elections and would not leave the ANC, which he acknowledged was torn apart by the storm around Zuma and Ngcuka.

Maduna admitted that the setting up of the Hefer commission two weeks ago was an attempt to stop the bleeding in the movement, "cauterising the wound" inflicted by the continuing backstabbing, smear campaigns and allegations of spying and misuse of office.

Maduna also emphatically denied media reports that he recently threatened to resign after a fight with Zuma in a cabinet meeting.

The terms of reference of the Hefer commission were broadened this week to include a probe into whether Maduna and Ngcuka misused their offices "due to past obligations to apartheid".

The commission was appointed originally to investigate allegations that Ngcuka was an apartheid informer, which surfaced in the wake of his comments that there was prima facie evidence of corruption against Zuma.

As minister responsible for the investigation, Maduna has increasingly been drawn into the brawl.

Furious, but in fight-back mode, Maduna spoke of a month-long campaign waged against him and Ngcuka in e-mails circulated to the media and the ANC, calling the two men "untouchables" who use their offices to target people selectively.

"It's utter rubbish," Maduna said.

On September 15 he received a letter from Kebble in which allegations were made and responses demanded.

"One of the allegations was that Bulelani and I were being controlled by the CIA," Maduna said.

"Kebble copied the letter to the president, the minister of intelligence, the minister of safety and security, to Bulelani and the national commissioner of police, in a clear campaign against me. I ignored the letter, because I thought I should not stoop so low ."

Maduna said on Monday he received another letter from Kebble, copied to others, that repeated the allegations while adding that the justice minister received a number of gifts, including a luxury motor vehicle for his personal use.

"He said the car has since been sold," Maduna said. "My car at home smokes. It will not survive the election campaign. I have never had a luxury car for personal use."

Maduna said he told Mbeki this week that while both of them were concerned about the allegations, the smear campaign should be included in the brief of Judge Hefer.

"I told the president: 'You are concerned, you want clean government. Expand the commission and ask the judge to subpoena them . Because I have never instructed prosecutors and members of the Scorpions to target any individual.' "

Kebble, who faces prosecution by the Scorpions for alleged fraud at Western Areas mine, had sent a complaint to the public protector, accusing Ngcuka of using his position to achieve his own ends. He said this week he was not attacking Maduna, but merely informing him of problems in his department that needed to be addressed. At a news conference this week, the mining magnate also lashed out at Ngcuka for a briefing recently to black editors on the Zuma affair, where he allegedly made comments about Kebble.

Maduna also wants the Hefer commission to probe allegations made in parliament in 1997 by De Lille that he was an apartheid spy, which she recently repeated to the media. He again said he was instructing his lawyers to pursue a defamation case against her.

"I am going to fight her in a separate suit," Maduna said.

On the nepotism accusations levelled against him this week by Mike Tshishonga, the deputy-director general in the justice ministry, Maduna denied he was involved in the appointment of liquidators, an issue already rectified by Pravin Gordhan, the revenue services commissioner. Maduna alleged that Tshishonga was being used by "certain circles" to which the official could be connected and hinted that Tshishonga had an axe to grind after being rapped over the knuckles for poor work performance.

"Mike is the most timid public servant," he said. "At worst he is the sort of person who would not be able to box himself out of a wet paper bag. You can print that."