It comes after talks between bus company Stagecoach and the Transport and General Workers Union (TGWU) broke down.

The 500 drivers will now be balloted over industrial action and if they decide to go ahead it could hit services across the county.

There is anger that drivers in Carlisle have been offered a bigger pay rise than their colleagues elsewhere in Cumbria because of a shortage of staff in the city.

Discussions have been taking place since November and two separate offers have already been rejected.

A spokesman for Stagecoach says the pay offer has now reached the maximum the company can afford.