Mr Davies has criticised an e-mail sent to him by the presiding officer's office and said he refuses to be silenced.

It follows an incident last month in which Mr Davies leaked documents from the business committee, including details of Labour's plans for performance-related pay for teachers.

David Davies: Will fight alleged "gagging"

He received words of warning from Assembly Business Secretary Andrew Davies, who said the Monmouth AM must follow the rules of confidentiality.

Andrew Davies, though, has said the latest situation was nothing to do with him and referred Mr Davies to the Assembly's Presiding Officer Dafydd Elis-Thomas.

"It is a matter between David Davies and Dafydd Elis-Thomas," said Andrew Davies.

"Since the matter was discussed in the business committee, it has not been discussed with me by the presiding officer or any member of the business committee."

However, Lord Elis-Thomas, who is on holiday in Italy, said he was unaware of the incident, which has arisen during the Assembly's summer recess.

Confidentiality clause

The draft document that David Davies has been sent reads: "...papers being considered by the business committee will remain confidential until either a decision has been made on the handling of that paper or they enter the public domain (usually at a full plenary meeting)."

Mr Davies has complained that the wording is too loosely written and would effectively gag him from speaking out on key issues.

The draft would also leave open who would decide which criterion applied to which document. He claims to be the only member of the business committee being asked to sign.

Temporary leader

Earlier this week, David Davies was embroiled in a Conservative Party row over who should take over from Rod Richards as party leader, following allegations that Mr Richards had assaulted a woman in London last month.

As deputy leader, Mr Davies was quickly installed as temporary leader while Mr Richards fought the charge, which he strongly denies.