The ruling body of the Scottish Secondary Teachers' Association has recommended that members vote against the �200m deal.

BBC Scotland Education Correspondent Ken Macdonald on the SSTA decision

The salaries committee of the country's largest teaching union, the Educational Institute of Scotland, has already turned down the 15% pay rise which was put forward on Friday by the Convention of Scottish Local Authorities.

The SSTA said the extra hours demanded of teachers will be filled with politically-driven strategies instead of pupil-driven work.

Proposals to reduce holidays

A full ballot of both unions' members will be held soon.

The smallest professional body, the National Association of Schoolmasters and Union of Women Teachers, has not said what its recommendation to members will be but it has publicly dismissed the package as "30 pieces of counterfeit silver".

This latest pay and conditions offer runs over three years and includes average pay rises of 15%, a cut in classroom sizes and a pledge that working hours will not be increased.

But in return teachers are being asked to give up five days' holiday, run homework clubs and hold summer schools.

The ongoing dispute is set to intensify further in light of the rejection calls from the two biggest unions.

Negotiating committee

The rift between teachers and the Scottish Executive appeared to widen on Tuesday when Education Minister Sam Galbraith threatened to abolish the Scottish Joint Negotiating Committee - the body which negotiates pay deals for teachers.

He has refused to say what might replace the SJNC or whether future pay and conditions offers will come straight from the Scottish Parliament.