Green Party leader and general election hopeful Keith Taylor faces a five-year ban as a Brighton and Hove city councillor.

The group convenor holds one of the few hopes of the Greens gaining their first seat in the Commons.

But his prospects at the polls could be damaged after a complaint against him to the national Standards Board.

An ethical standards officer today began an investigation into allegations he breached strict confidentiality rules.

The complaint was made after Coun Taylor, who represents St Peter's and North Laine, stormed out of a confidential meeting and spoke publicly against plans to expand Shoreham airport.

His claims the decision to call for an investigation is politically motivated have been staunchly denied by his Labour rivals.

He said: "This is a shabby move by New Labour to stifle democratic debate by gagging me and damaging my prospects to become the Green Party's first MP in the forthcoming general election.

"The expansion of Shoreham airport is bitterly opposed by residents and I only agreed to join the board on the basis that I would be able to represent their voice and support alternative uses for the land.

"From the outset of the inaugural meeting it became clear board members were expected to rubber stamp recommendations from officials to expand the airport and keep our traps firmly shut.

"The board's terms of reference, which demanded secrecy, were not issued ahead of the meeting and I felt that I and other members were being put into an untenable position.

"I am confident this investigation will recognise there is no case to answer and voters will punish the Labour Party where it hurts, in the ballot box."

Councillor Don Turner chaired the first Shoreham Airport Owners Board and made the official complaint.

He claimed an agreement the meeting would be confidential had been broken.

He said: "I made this complaint because I feel this was a serious breach of confidentiality and it was my duty to report him.

"This has nothing to do with gagging. The rules are there and all I'm doing is making sure everyone obeys those rules."

Council leader Ken Bodfish said he could not comment on a case before the Standards Board.

But he said: "It's critical confidentiality is respected when appropriate."

Coun Taylor resigned from the new Shoreham Airport Owning Authorities Board after he stormed out of the first meeting.

Councillors from both Brighton and Hove and Worthing are seeking private investment in the site and have drawn up a marketing document.

But the plans have been described by the Greens as the first stage of transforming it into "Brighton International Airport."

The letter to Coun Taylor confirming the case has been referred says it is alleged the day after he left the meeting "a reporter contacted the complainant and asked him to comment.

"The complainant states it was clear that the reporter had a copy of or had seen the relevant papers, and that he had had a discussion with Coun Taylor after the meeting."

An ethical standards officer can rule there is no case or that disciplinary action is not necessary.

The case could go before the council standards committee, where a three-month suspension can be imposed.

The complaint can also be handed to the adjudication panel for England which has the power to disqualify a councillor for five years.