The Congress of the People (Cope) said its former election co-ordinator Mlungisi Hlongwane, who returned to the African National Congress (ANC) on Thursday, was suspected of being an ANC mole.

They also blamed him for the late and "embarrassing" start to their campaign for the April 22 elections.

"[Hlongwane] was identified as a possible ANC mole following a number of acts of sabotage which were meant to embarrass the party," read a statement from Cope spokesperson Sipho Ngwema.

Hlongwane, who joined the ANC breakaway group last year, announced his return and that of Cope's Gauteng chair Siphiwe Thusi. At the announcement in Johannesburg he was flanked by ANC policy head and Transport Minister Jeff Radebe, ANC spokeswoman Jessie Duarte, and Thusi.

Radebe had initially been billed to make an announcement of "national importance" at Talk Radio 702's offices.

The broadcaster, which last year hosted the "divorce" from the ANC announcement by Cope co-founder Terror Lekota, removed its branding from the podium and brought ANC branding in.

However, at the last minute, the broadcaster cancelled the briefing on its premises, saying it had since come to light that the announcement was "not of national import". As reporters left for the ANC's headquarters Luthuli House, an impromptu press conference was held in the parking lot instead.

Hlongwane cited concerns over anti-Xhosa sentiments and claimed election candidate lists were manipulated and formulated without proper input.

He claimed that many Cope insiders were unhappy, and said Cope's presidential candidate Mvume Dandala was put onto the list at the last minute through the intervention of former prosecutions boss Bulelani Ngcuka.

Ngcuka had been accused of running a political campaign in his handling of the corruption investigation against ANC president Jacob Zuma.

"Today I have voluntarily decided to acknowledge my acute disappointment in Cope," he said, reading from a lengthy speech.

It began with a quote from HG Wells and ended with an extract from Rudyard Kipling's poem "If".

He apologised to people who had supported him and had joined the party on his urging, including his family, and to people who had ploughed funds into the party.

He also distanced himself from any "anti-Zuma" groups. He said that some people had got "under my skin" and made him react negatively to the ANC ... "it is a decision one regrets".

He had waited until the ANC's list process was complete before announcing his decision.

He hoped the ANC would accept his application to become a member again and he would talk to the SA National Civics Organisation about how he could become involved, after he resigned his leadership position when he joined Cope.

Former president Thabo Mbeki had no role in the setting up of Cope, he said to journalists picking his brains on speculation that Mbeki had a role in the party, which was formed initially by people upset by his forced resignation last year.

However, in a statement, Ngwema accused Hlongwane, who announced his defection to the ANC at a Cope conference in Sandton last year, of tabling a manifesto that was a carbon copy of the ANC's at the party's Bloemfontein launch conference.

"His incompetent handling of Cope's election campaign... caused the party major embarrassment and led to begin our election programme very late. His actions seriously disrupted our elections activities including the loss of by-elections," they continued.

He had been accused of tampering with the party's election lists and spreading disinformation about leadership contests, which led to embarrassing news reports.

He was also accused of tampering with the party's election lists which led to an internal investigation.

They claimed his business interests were threatened through his association with the ANC breakaway party and said wryly: "We believe he will be a useful asset to the ANC and we wish him well."

Cope deputy president Mbhazima Shilowa had been managing the election campaign "following our credible suspicions", the party said.

Radebe welcomed Hlongwane back to the ANC.

"We are receiving him with warm hands. He has always been a seasoned leader of the ANC and civic movement."

Hlongwane, who had also been number two on the Gauteng election list would address Vaal region challenges, he said, adding that the ANC had decided it needed to embrace all of its former members.