Unite the union has warned National Express that its bid to take over Stagecoach comes at a time of industrial unrest amongst the target firm’s staff.

Unite said its members are currently involved in around 20 separate disputes with Stagecoach across the UK over pay and other related issues.

It said these disputes may result in industrial action across Stagecoach’s UK network during the autumn and winter.

National Express Group Plc announced on Tuesday it is in talks to buy Perth-based Stagecoach in an all-share deal that would value the Scottish transport firm at about £445 million.

Stagecoach founders Brian Souter and his sister Ann Gloag announced in April a 10-year plan to reduce their shareholdings in the firm from 27% to 5%.

Unite general secretary Sharon Graham said: “Unite members all over the UK are voting for industrial action right now over Stagecoach’s ‘penny pinching’ on pay.

“Stagecoach’s board should be in no doubt that Unite is now wholly dedicated to advancing the jobs, pay and conditions of our members.

“The National Express board should be similarly advised that should their takeover bid for Stagecoach be successful, Unite will oppose the asset stripping and wage cuts that usually accompany such City manoeuvers.”

Unite national officer for passenger transport Bobby Morton said: “Unless Stagecoach’s board sends a clear message to its local operators that they are to give their staff a decent pay rise, there will very likely be separate strikes all over its bus network come October, whether there is a change of owners or not.”