Fire fighters have held unofficial industrial action against changes to an agreed pay deal.

Staff announced they will only answer 999 calls as they began a "work to rule" protest.Meanwhile the Fire Brigades Union's high command is considering whether to call for further official walkouts.

Employers have warned, however, that there will be no change to plans to implement the new pay deal in two stages.

They say the seven per cent award, which is due this month, was conditional upon modernisation moves which are not yet complete.