The African National Congress ousted a leading member of a parliamentary committee probing a multi-billion rand arms deal and moved party loyalists onto the panel on Monday.

The move followed statements by President Thabo Mbeki and several ministers that the R43-billion deal was above board and that anyone suggesting otherwise was attacking the ANC government.

Andrew Feinstein, the leading ANC member of the public accounts committee who had championed a probe into the deal, was ousted and replaced by the party's deputy chief whip, Geoff Doidge.

Political analysts expressed concern about the government's action.

"This is an open clash between parliament and the executive," said Sampie Terreblanche, a political analyst. "This is a constitutional crisis. It would be a sad day if this would be the first sign of presidential authoritarianism."

The ANC already had a majority on the committee, which is headed by a member of the Inkatha Freedom Party, but had made sure that it did not flex its political muscles in a forum that has traditionally been non-partisan.

But the ruling party shattered the truce on Monday as it moved several other loyalists including chief whip Tony Yengeni onto the committee and its study groups.

The arms deal signed in December 1999, involving arms firms in Germany, Italy, Sweden, Britain, France and South Africa, is supposed to generate offset investments worth R104-billion and create 65 000 much-needed jobs.

But allegations of bribery and corruption have surrounded it, and a preliminary study by the auditor-general last year called for an in-depth review after finding serious flaws in procedure.

The ANC said Monday's moves were aimed at beefing up its team on the parliamentary committee, as other parties had already done, because of the serious nature of the probe.

But analysts put a more sinister interpretation on the changes.

"There is a palace revolution in the ANC," said Richard Calland of the Institute for Democracy in South Africa. "This is the end of the road for this committee as far as it has operated impartially in the past."

Willie Breytenbach, professor of political science at Stellenbosch University, said it was a bad day for a country still shaking off apartheid. "This is a massive step backwards in terms of consolidating our very fragile democracy," he said. "This is muzzling the independence of those institutions that are supposed under the constitution to ensure accountability and transparency."

Steven Friedman, at Johannesburg's Centre for Policy Studies think tank, said the move was ill-advised.

"It is going to backfire," he said. "The negatives are going to outweigh the positives." He said the attitude of the government and of the party - that an attack on one was an attack on all - still contained far too much baggage from the days when it was outlawed and its members persecuted by the apartheid authorities. "Nobody can doubt that the government has handled this in such a way that it appears to be covering something up," Breytenbach said. "This is a bad start to the year."

With acknowledgement to Reuters and Independent Online.