Testing time for education ministers: Judith Judd examines the Government's response to the threat by teachers to disrupt national testing

HOW serious is the threat by teachers to disrupt the Government's programme of national testing and assessment?

Education ministers appear to believe that any action will not be effective. They are reluctant to be drawn into discussion of the legality of the National Association of Schoolmasters/Union of Women Teachers' vote to boycott all testing and assessment on the grounds that 'we haven't got there yet'.

If there is disruption, they argue, parents will be angry because parents at some schools will know how their children have done while others, in schools hit by the boycott, will not. They also believe it is a catch-22 situation for the NAS/UWT. If the action attracts little support, the union will be embarrassed. If it is successful, public opinion will turn against teachers.

Headteachers, however, are almost certainly right to suggest that ministers are underestimating the disruption which a boycott could cause, even if only a substantial minority of teachers support it.

The main threat is to the tests for 14-year-olds in June in English, maths, science and technology. The NAS/UWT is threatening to boycott all these. The 180,000- member National Union of Teachers, which will ballot its members in May, is likely to join the boycott of English tests, but not the other subjects.

Tests for seven-year-olds which began last month and continue until the middle of next term may escape. Only the NAS with just 20 per cent of its members in primary schools is threatening to boycott these. In the case of 14- year-olds, it will be messy. Since union membership is not distributed evenly throughout schools, individual schools will be affected very differently.

Nigel de Gruchy, the association's general secretary, joked on Tuesday that it could be assumed that the 43 per cent of members who failed to vote in the ballot were in favour of the boycott 'as the Government does with parents who don't vote in ballots about schools opting out of local authority control'.

That is too sanguine. There will be divisions of opinion among NAS members, but the tests are in jeopardy in those schools where the union's members are concentrated: 52,000 teachers backed the boycott in a ballot.

English tests, in particular, are threatened by a combined boycott of NAS and NUT members. Ministers still hope that the NUT will stop short of action, but the union is simply keeping its powder dry. To comply with trade union law, its ballot on boycotting English tests cannot take place until May. In a preliminary ballot last month 91 per cent of its English teacher members supported a boycott. About a third of NUT members are in secondary schools.

The key to the dispute lies in the attitude of heads. In the pay disputes of the 1980s most refused to support striking teachers. This time it will be different. Heads will not join the boycott but they will call off the tests if they feel teachers' action will mean the results give an unfair picture of their schools, and will advise governing bodies not to discipline teachers who join the boycott.