Alan McCombes claims the SSP has a right to confidentiality

The News of the World has requested the internal minutes, which it claims would help defend a defamation case brought by former SSP leader Tommy Sheridan.

Judge Lady Smith jailed Mr McCombes for 12 days after he ignored a deadline to release the papers.

The party insists the minutes of an executive council meeting are private.

The documents in question cover the meeting where the resignation of Mr Sheridan as leader was discussed.

You are flouting an order of court. No-one is entitled to do that Judge Lady Smith

At the Court of Session in Edinburgh on Friday, Lady Smith granted a News of the World motion and ordered Mr McCombes to hand over "all and any" documents.

The normal rule in such circumstances is for documents to be submitted in a sealed envelope and for arguments about confidentiality to be made then.

Paul Cullen QC, representing Mr McCombes, had told the judge his client did not intend to comply.

Court punishment

When a deadline of 1430 BST passed, Lady Smith ordered Mr McCombes to be held in custody until a week on Tuesday to consider his position.

"It has been made quite clear to you that you are flouting an order of court. No-one is entitled to do that."

She warned him that if he did not change his stance it would be "highly likely" she would make a finding of contempt of court and he would be punished accordingly.

I've said all along it's a matter of principle, it's a matter of conscience Alan McCombes

Lady Smith also granted a warrant for messengers-at-arms to search for the documents in question.

Speaking just before he returned to court Mr McCombes said: "I've said all along it's a matter of principle, it's a matter of conscience."

He added: "It's not the first time as a Socialist I have been in conflict with the court, I'm sure it won't be the last time."

Afterwards, SSP party convener Colin Fox said: "Our colleague, comrade and friend, Alan McCombes, has been sent to jail for defending a fundamental principle - the private and confidential documents of the SSP should remain the property of the party."

It is thought the party leadership has urged Mr Sheridan to drop his case against the News of the World.

Rather than wanting to help Mr Sheridan by refusing to release papers, it is thought the SSP is more concerned over the effect his defamation action is having on the party.

Newspaper allegations

It is believed he may even be expelled from the party he helped set up over the issue.

The Court of Session hearings stem from the time Mr Sheridan was leader of the SSP.

The Glasgow MSP, who co-founded the SSP with Mr McCombes, agreed to step down in November 2004 citing family reasons.

His decision came shortly after allegations about his private life were published by the News of the World.

He denies the claims and a full hearing is due to begin on 4 July.