Bus drivers at First Aberdeen have backed plans to begin indefinite strike action starting next week.

It comes after a mass meeting on Thursday with Unite Scotland officials amid an ongoing dispute over planned changes to contracts.

Members of the trade union have already taken part in stoppages but the current strike action ends on Saturday.

A further indefinite period of action will start on Friday, April 6, after the proposal was ratified at Thursday's meeting which included more than 200 drivers.

First Bus' proposals for the new contracts have been criticised for increasing drivers' working hours for reduced wages as well as for reduced sick pay, annual leave and holiday pay and the scrapping paid breaks.

The company drew up the plans following a reduction in passenger numbers across the city.

Both sides had earlier said they were close negotiating an agreement.

Unite First Bus branch convener Graham Gavin said "Andrew Jarvis the First Bus managing director likes to talk about give and take in these negotiations.

"Well it's Unite members that are doing all the giving and First Bus doing the taking. The point of view of our union members is that 'they want the shirt off our back'.

Joint convener Mike Flinn added: "First have to recognise that their reputation as a company is being hugely damaged by their own intransigence. They might as well de-brand their buses right now.

"As I recall Unite offered to go to arbitration in the first place but First rejected the offer out of hand."

However, First Bus criticised the manner in which the decision for fresh strike action was agreed.

Andrew Jarvis, managing director for First Aberdeen, said: "Everyone at First Aberdeen is extremely frustrated and bitterly disappointed by the outcome of the latest Unite the Union branch meeting.

"A revised proposal was negotiated by both parties to a point, which we believed met all but one element of all concerns raised by Unite members, so we cannot understand why this proposal was not put forward for an official ballot.

"We are very surprised that the latest branch meeting did not result in the revised proposal being put to a ballot in an official capacity of one member getting one anonymous vote, which is then officially recorded and counted.

"The branch meeting reportedly contained less than a third of the driving workforce and their members were asked to take part in a straw-poll style raising of the hands vote.

"This is simply no way to determine an official outcome that is reflective of the entire workforce in this scenario."

He added: "We had requested an urgent meeting on Friday with our trade union colleagues in order to try and end this dispute, however, we have subsequently been informed that the trade union official is unavailable."