Colin Fox said the party had to learn lessons

Mr Fox told the SSP conference in Glasgow the party was regaining support as people now realised it had told the truth about the former leader.

The conference is the first since Mr Sheridan won a £200,000 defamation case against the News of the World.

He has since split from the SSP and founded his own party, Solidarity.

The shadow of Mr Sheridan loomed large over the opening session of the conference, attended by nearly 200 people.

Learn the lessons

The event at Glasgow Caledonian University saw delegates debate issues arising from the split.

In his leadership speech, Mr Fox told activists: "The SSP has come through a real-life horror move - a nightmare so acute it would have broken lesser parties completely.

"Yet with every passing week, more and more people are overheard saying it was the SSP that was telling the truth all along."

Mr Fox said the party must learn the lessons of recent events while reaching outwards to build a mass party.

He said the 2007 Holyrood elections were "critically important".

Tommy Sheridan has split from the SSP

The opening debate saw massive backing for a resolution which said any person who quit the SSP would be welcomed back without recrimination.

John Milligan, of the RMT transport union, told the conference parts of the SSP leadership had "significantly failed" the membership and were to blame for Mr Sheridan's departure.

He said the union was deciding whether it should remain affiliated to the SSP.

Opening the debate, Richie Venton of the SSP's national executive, said 30% of the SSP had gone to Solidarity but the "overwhelming majority" had stayed.

"We can stoop to anger and vitriol, or rise to mature socialist politics," he said.

Swingers' club

In a later debate delegates backed a resolution calling on SSP members not to resort to "the state's courts" to seek redress for politically-motivated attacks.

But one speaker, Mary McGregor, told the conference of "the elephant in the room" in the debate - a video made public last week by the News of the World.

This purportedly shows Mr Sheridan admitting to an SSP colleague, George McNeilage, that he had attended a swingers' club.

Mr Sheridan has denounced the tape as a forgery but the newspaper has insisted it is genuine.

Ms McGregor condemned the tape.