Harare - Supreme Court Justice Ahmed Ebrahim, Zimbabwe's most senior independent judge, has resigned, the government said on Saturday.

He was the seventh judge to step down in less than a year in which the government has repeatedly violated the rule of law, ignored court orders, packed the courts with ruling-party cronies and threatened other judges with violence.

Justice Minister Patrick Chinamasa, quoted in the state-controlled daily Herald, said Ebrahim would leave office in May. "He has not given any reasons," said the minister.

The announcement came a day after Chinamasa said he would effectively reinstate a law - struck down by a court led by Ebrahim on Wednesday - which civic groups say will severely restrict independent scrutiny of polling and simplify vote rigging in elections on March 9-10.

Ebrahim was not immediately available for comment.

His court ruled that the law had been illegally bulldozed through parliament by the government. Chinamasa said he would bring it back in the form of regulations.

Internationally-respected former chief justice Anthony Gubbay was forced under threat of violence to resign in March last year, and President Robert Mugabe immediately appointed controversial pro-government judge Godfrey Chidyausiku, also a long-term political ally, to replace him.

He was appointed over the head of three other more senior supreme court judges, including Ebrahim.

Chidyausiku and three other pro-Mugabe judges appointed since then have repeatedly used their majority in the supreme court to deliver rulings favourable to the regime.

Judge Wilson Sandura is the last independent judge left in the supreme court. The last judge to resign was High Court Justice David Bartlett who went in December after authorities ignored his orders to investigate parliamentary speaker Emmerson Mnangagwa who, when he was justice minister, illegally ordered the release from prison of a convicted bank robber reported to be his illegitimate son, and gave the takings of the robberies to his (Mnangaghwa's) mistress.

Judge Michael Gillespie stepped down in July, and cited "the breakdown to mob rule" as the regime "renounces its commitment to the rule of law".

Judge James de Vittie resigned around the same time when he was personally threatened with attack by a senior member of Mugabe's movement of so-called guerrilla war veterans, because the judge had annulled three ruling-party victories in parliamentary elections in 2000 on the grounds of violence. No action was taken against the veteran.

The onslaught against the judiciary began in December 2000 when the supreme court under Gubbay ruled that Mugabe's campaign of forcible occupation of white-owned farms was unlawful and ordered the regime to restore the rule of law.

The ruling was ignored, and ruling-party supporters stormed the supreme court, threatening to attack the judges.

The judges were later issued further threats of violence by militants and Mugabe refused a request to provide them with security. - Sapa-DPA