I agree that this is not desirable. At least three of the six do not have a vote, so should avoid taking a strong line on any controversial issue and thus influencing those who do have votes. In any case it is not healthy if the staff become a bloc. But I can understand how these anomalies just grow, and how difficult it is to shift them.
The curriculum working party has no delegated power, so any conclusions have to come to the full governing body. I know this does not remove the problem, since if what governors want is a change, they will not easily get any recommendation past the staff bloc. You may, however, when it is an important matter, be able to push for it to be referred formally as an open question to the next full meeting.
If I were a member in such a case, I would find some way of reminding the teacher governors that they are governors with minds of their own and, as such, should not always act predictably as an interest group. Teacher governors want - and sometimes need - the rest of us to stick up for them if their role is being restricted by head, chair or local education authority - we therefore have a right to expect them to behave like governors.
To tackle the question of the heavy presence of staff on this group, you must go back to its origins. The proper procedure is for the full governing body to discuss the conduct of committees and working parties, ideally at the beginning of a year. They should determine, for instance, whether the committee elects its own chair or has a chair elected by the governors. They should also lay down rules on co-options and visitors. A degree of formality in this will make it easier for you to resist casual assumption of the right to attend. I am all for open committees, but to work well these require good behaviour by all concerned. You may have to be more restrictive for a while.
Can the chair suggest for a start that it is unnecessary for both head and deputy to attend? Then, if you have two teacher governors you could suggest that it is enough for the non-governor teachers to take turns. Alternatively, one of the teacher governors could give way to a second expert colleague. At the meeting, you must remind the visitors or co-optees if they forget that they should not try to influence the discussion too heavily. This is yet another case where governors complain about a situation which they have passively allowed to arise. I know it's hard but you must each accept responsibility for putting it right.
Questions for Joan Sallis should be sent to Agenda, The TES, Admiral House, 66-68 East Smithfield, London E1 9XY. Fax: 0171-782 3200.