Teachers' unions were attacked for damaging the image of the teaching profession by the Conservatives' education spokeswoman, Theresa May.

Speaking at the National Union of Teachers' annual conference in Cardiff, Ms May accused teachers of maintaining the "last bastion of reconstructed trade unionism".

"Images of teaching unions calling for civil disobedience and threatening industrial action ... does incalculable damage to the reputation of the teaching profession," said Ms May.

May: Unions are doing "incalculable damage"

Teachers were losing the respect of the public by "barracking government ministers" and taking industrial action.

But unlike the heckling which had disrupted the education secretary's speech earlier in the day, Ms May's speech failed to provoke any angry responses from her audience - although her arrival was marked by a few delegates pointedly walking out.

Confrontation

There had been speculation that the widely-trailed attack on teachers' unions might lead to a conference hall confrontation - with the shadow education secretary seeking a share of the heckling usually accorded to ministers.

But instead her criticism of teachers' unions drew loud ironic cheers and her speech drew little reaction from delegates.

After the address, Ms May rejected suggestions that she had deliberately intended to provoke - but had wanted a genuine dialogue with teachers.

The speech also presented further details of the likely shape of the Conservatives' education policy at the next general election.

This blueprint for a Conservative administration's education policy calls for a radical reduction in bureaucracy and a delegation of power to schools.

The national pay scales for teachers would be abolished and individual schools would be able to set their own salary arrangements.

She also promised that a Conservative government will introduce a national funding formula for schools, which would end inequalities in funding between different parts of the country.

There would also be a network of "progress centres" for disruptive pupils and the ending of targets for reducing exclusions.

There was also a promise that teachers accused of mistreating or abusing pupils will be allowed to retain their anonymity, until the point at which police press charges.