African National Congress MP Andrew Feinstein on Thursday resigned from parliament, citing disappointment over the government and his party's handling of the controversial multi-billion rand arms deal.
Feinstein said he had been unable to play a meaningful role in the national assembly, or as a member of the standing committee on public accounts (Scopa).
"It is not a matter of being sidelined... I have been unhappy with the way the government and ANC in parliament have handled the situation (the arms deal)."
He would, however, remain a member of the party.
Feinstein was replaced as head of the ANC's study group in Scopa in January, following disagreements with the ANC over the probe into the deal.
He said he had decided not to take part in further Scopa proceedings after the ANC study group had instructed him not to speak in Scopa unless his comments were cleared by his colleagues.
This had followed a formal complaint to ANC Chief Whip Tony Yengeni over his refusal to vote in the committee, and in the national assembly, in support of a motion of confidence in Speaker Dr Frene Ginwala.
The House had debated a complaint from United Democratic Movement leader Bantu Holomisa that Ginwala was biased in her actions concerning the arms deal.
Feinstein said the fallout with his colleagues revolved around whether the committee, in a resolution in November last year, had in fact called for the Special Investigating Unit - then headed by Judge Willem Heath - to be included in the multi-agency probe.
The arms deal is being investigated by the Auditor General, Public Protector and the directorate of public prosecutions.
"I have felt a little uneasy over the past few months... (the party) was not happy with my refusal to support (the line of the arms deal)."
Feinstein said he had made a decision earlier this year to wait until the report on the probe was finalised before leaving parliament.
However, the release of the report was continually delayed.
"I don't want to pre-empt the investigation, but I hope it is thorough... there have been some things that concern me."
He was also disappointed by the disintegration of Scopa as an effective watchdog body, which at the end of last year, he said, was a highly-skilled, effective and non-partisan committee.
Both the ANC and Democratic Alliance were responsible for the breakdown of the committee, said Feinstein.
Both parties made major changes to "strengthen" their delegations on Scopa, and since then the committee had been plagued by in-fighting and political wrangling.
Feinstein said he had not as yet made a decision on his future, although he had received a number of offers, mainly from the private sector.
He would make a final decision on this before the end of next month.
The ANC said in a statement that it had accepted Feinstein's resignation, and was happy with the way the Scopa study group had conducted itself on the arms deal.
"We are especially satisfied with the way in which we have dealt with the investigation into the arms acquisition process," said Scopa spokesperson Vincent Smith. - Sapa