The South African Government has been accused of resorting to censorship policies reminiscent of the apartheid era in a bid to silence its critics in the media.

The ruling African National Congress is pushing a series of measures which would, opponents say, undermine freedom of speech, criminalise investigative reporting and threaten whistleblowers in the civil service with prison sentences.

The Protection of Information Bill, currently before Parliament, where the ANC holds a two-thirds majority, is part of two-pronged effort to bring the media under closer control.

The second stage is a proposed Media Tribunal which would make South Africa’s press – often accused by the Government of being anti-ANC – answerable to Parliament.

In a petition launched on Saturday opposing the measures, a host of South Africa’s leading writers, including Nobel laureate Nadine Gordimer, hit out at a return to apartheid-era censorship. The writers described the tribunal as the creation of the “Word Police”.

In recent years South Africa’s press has been increasingly occupied by the rise of the “tenderpreneurs” – a new, wealthy elite who use their political connections to benefit from state contracts.

Many of the sweetheart deals have come through the largely discredited Black Economic Empowerment (Bee) programme that was meant to improve the lot of disadvantaged blacks but has helped to create a new elite.

This month a company headed by Jacob Zuma’s 28-year-old son Duduzane was shown to have received more than 80 million in shares from Arcelor-Mittal. The company said the stake in the South African arm of the steel giant was allocated for “strategic assistance” with meeting its Bee requirements. Other beneficiaries included the reported girlfriend of the deputy president and an “empowerment advisory counsel” to the President.

The information bill would give the power to heads of government agencies to classify whole swathes of information on the grounds that it was in the “national interest”. This would then make disclosure of related information a criminal offence punishable with up to 25 years in prison. Lawyers are concerned with the vague language employed in the draft.

The country’s leading legal body, the General Council of the Bar, said several provisions of the bill were “plainly contrary” to freedoms enshrined in its much-admired constitution.

Critics accuse the ANC of exhibiting a paranoid tendency in response to legitimate journalistic criticism of abuses of power.

The information bill’s backers insist that it is intended to curb the worst practices of the sensationalist media and guarantee minimum standards in a sector dogged by uneven quality.

However, business leaders have joined journalists and writers in condemning the proposals saying they will undermine the fight against corruption and damage the country’s standing internationally.

In the face of a storm of protest the ANC has indicated that it may dilute some of the intended measures, but voices of moderation have been hard to hear over the din of accusations being traded.

The arrest this month of a reporter with the Sunday Times, Mzilikazi wa Afrika, has further stoked tensions. He was taken in on fraud charges within days of the publishing of an article implicating police chief Bheki Cele in a “suspicious” property deal.

South Africa’s disgraced former police chief and ANC stalwart Jackie Selebi has just been imprisoned for 15 years, in what the ruling party insisted was the turning of a new page on corruption.