Greg Dempster is right - “there is more than one voice in teaching, so one union cannot speak for them all” (“Sometimes the profession can benefit from disagreement”, TESS, 20 April). Those who argue in favour of one union overlook a number of important points.

There are ideological differences. For example, Voice: the union for education professionals does not take industrial action; others favour such tactics. Plus, some teacher unions, such as Voice, also represent classroom assistants, technicians and other education professionals.

Scotland, England, Wales and Northern Ireland have their national unions and are represented by UK-wide unions. But in Scotland, the size-based dominance of the EIS can make it difficult for other voices to be heard in negotiations, because of the EIS’s ability to outvote other bodies. This was shown during the SNCT negotiations last year when the EIS, on a close result of less than half of its membership, and Cosla joined forces to overturn the wishes of most teachers and push through a package that Voice, NASUWT and SSTA had all voted to reject.

The accelerated increase in our membership during that period makes clear teachers’ desire to be in a position to choose a union that reflects their personal viewpoint and values.

Unions are about more than conference controversy. After consulting its members, Voice has moved from traditional debate-based conferences to CPD- based events open to members and non-members.

Big isn’t necessarily beautiful. Not everybody wants to be part of a monolithic organisation. Many Voice members value the personal service they get from a smaller, independent organisation that is large enough to operate successfully on the national stage but knows many of its members personally.

Diversity of views is to be welcomed.

Jennifer Hannah, senior professional officer (Scotland), Voice: the union for education professionals.