The brakes could be put on Scotland’s major bus routes this autumn if 1500 workers from Perth -based Stagecoach vote for industrial action over a pay dispute.

If the ballot for industrial action is successful then bus services, remote local communities and major events - including COP26 - are expected to be “severely disrupted”.

The Unite Scotland ballot opened on September 21 and covers major bus depots across the country, including ones in Perth, Dundee, Angus and Fife.

Drivers, engineering staff, administrative workers and cleaners are involved in the dispute and if industrial action goes ahead then strikes, and action short of strike, could begin by late October and last three months.

That, combined with similar issues with Abellio ScotRail staff members, could cause transport chaos to the COP26 climate change conference in Glasgow between October 31 and November 12.

The bus firm failed to reach an agreement with staff over pay, with the union claiming a below inflation rise has been offered.

The dispute comes as Stagecoach opens talks with rival transport firm National Express over a merger.

The terms of the potential deal would combine the UK’s two biggest coach and bus operators, with National Express owning about 75 per cent of the combined group and Stagecoach 25 per cent.

National Express has until October 19 to make a firm offer.

Concerning the pay dispute, Unite regional coordinator Dougie Maguire said: “Stagecoach’s stance has been nothing short of shocking, and it has infuriated the workforce who have continued to work diligently throughout the COVID pandemic.

“The Stagecoach Group is extremely profitable. It also directly benefits from millions of pounds of public funds every year through various Scottish Government schemes, not to mention benefiting from the UK Government’s furlough scheme for the last 18 months.

“If Stagecoach do not come to their senses, then many of the nation’s major bus routes will grind to a halt if our members vote for industrial action.

“Remote local communities and showcase events such as the COP26 climate change conference will be severely disrupted.

“This will be solely down to the group’s point blank refusal to make our members a fair pay offer.

“The solution is simple: give our members the pay rise they deserve or face widespread industrial disruption.”

In response a Stagecoach spokesperson said: “Local people who depend on buses to get to work and access public services, as well as local businesses struggling to recover from the pandemic, will be extremely angry at the threat of completely unnecessary disruption to their bus services.

“The threat of strike action is even more puzzling as we have already agreed a pay package with Unite covering members in several other parts of Scotland and they remain happy with the deal.

“In addition, union representatives have recommended their members accept the package that we have offered in the west of Scotland.

“The focus should be on protecting both the jobs of our people and the long-term sustainability of vital public transport services for the local community.”