Councillors accused of breaking rules by discussing tactics for an upcoming debate were busted when the email thread copied in the council clerk.

Members of Bearsted Parish Council were called out at a meeting when they talked about their plans to defeat or amend a motion.

The councillors were part of the faction on the council who are opposed to "Project A" – a scheme to move the allotments onto land recently donated to the parish council, so the village tennis club could be expanded over the site currently occupied by allotment holders.

The email chain which involved four parish councillors and some local allotment holders included the allegation that the clerk herself was one of three people who were "driving Project A forward at any cost".

The messages included discussions about what allotment holders should say during the public session of the council meeting and what amendments the councillors should propose to the scheduled motions about Project A.

At the start of each meeting, there is point at which councillors are asked to declare any interests, pre-determination or lobbying they have had on any issue on the agenda.

Three of the councillors – Denis Spooner, Richard Ash and David Hall – were present at the meeting, but made no such declaration, whereupon Cllr Sandra Knatchbull dramatically produced copies of the email exchanges and circulated them.

The clerk advised the council she had taken advice from the Kent Association of Local Councils (KALC) who had given the opinion that the email discussion was "clear evidence of pre-determination" and the councillors should therefore exclude themselves from the meeting.

But Cllr Spooner accused the authority, saying: "You are trying to stifle debate."

Cllr Ash, who had been copied in on the emails but had himself made no contribution to them, said: "Surely, if one simply receives an email, that cannot constitute pre-determination."

But Cllr Jon Hughes described his colleagues' actions as amounting to "conspiracy".

Council chairman Martin Broughton invited the three councillors to heed the KALC advice and excuse themselves, but Cllr Spooner said: "You have a misunderstanding of the role of councillors in the community."

He said it was perfectly reasonable and normal for councillors to discuss issues of concern with local residents.

The clerk confirmed the council had no means of compelling the councillors to declare pre-determination. She said: "It's down to them."

But she warned that if they stayed, it could open the way for a legal challenge to any decision that the council made on the subject.

The three councillors all stayed and played a full role in the subsequent debate an Project A.

The fourth councillor included in the email chain, Cllr Mike Harris, was not present in the council chamber for the meeting.