A poll of teachers has found widespread support for a merger between the three main teaching unions.

Of those polled for the Times Educational Supplement, 71 per cent backed fusion, between the National Union of Teachers, the National Association of Schoolmasters Union of Women Teachers and the Association of Teachers and Lecturers.

The survey found 18 per cent against the deal, and 11 per cent undecided.

Enthusiasm for the merger, which would create a "super-union" of up to 580,000 teachers, has grown recently, after more than a century of three separate unions existing.

Support for the deal was found to be highest among members of the largest of the unions, the NUT, at 80 per cent. This compares to 70 per cent of NASUWT members.

Of ATL members, 52 per cent backed the proposal. Speaking at their conference in Cardiff, president Julie Grant said: "The signatures show why the ATL executive has put the debate at the top of the agenda, not only unity but federation and other forms partnership.

"It will be for members to make the decisions about the future of their union in due course."

New general secretary of the NASUWT, Eamonn O'Kane, welcomed the poll's results.

"It underlines the need to think seriously about the future so a union like ours doesn't get out of touch with the feelings and views of our members," he said.

"It's only an opinion poll, there will be an enormous amount of work and discussion before any real partnership can emerge. Clearly, one has to recognise that in the ATL there is a majority but there are greater misgivings as well."