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

More than 900 drivers at four depots in the region - Slatyford and Walkergate in Newcastle, Sunderland and South Shields - are being asked to vote.

The result of the ballot will not be known for at least another week.

Steve Stewart, spokesman for Stagecoach said the company hoped strike action could be avoided.

'Impasse reached'

He said: "We are hoping that employees will not vote for industrial action. We have offered �8 an hour over the next two years which is a rise of 9.8%.

"We believe this is an exceptional offer."

The drivers being balloted include 200 members of the GMB trade union.

Brian Anderson, Newcastle-based representative for the TGWU, told BBC News Online on Friday: "We have reached an impasse with the company after rejecting the latest pay offer.

"We have only just balloted our members but cannot rule out the possibility of strike action.

"It is a postal vote and we will not know the results for at least seven to eight days."