Glasgow underground staff are to strike over a dispute about pay and holidays.
The 48-hour walkout from today by members of the T&G on is the fourth in the dispute and unions have promised to escalate their action unless demands are met.
T&G regional organiser Scott Foley said: "By failing to address the pay and conditions issues in a fair manner, the management at Strathclyde Passenger Transport (SPT) have done a great disservice to the travelling public in Glasgow.
"We regret any inconvenience to the public, who receive excellent service on a daily basis from our members.
"We urge the management of SPT to get round the table to discuss, in a meaningful way, the potential for a fair negotiated settlement which does not compromise the safety of the subway."