TGWU national secretary for transport Ron Webb, who is on the picket line, said the company has tightly secured the depot in scenes reminiscent of the 'Fort Wapping' dispute in the 1980's.
The strikes, involving nearly 150 drivers, will affect about 100 Tesco stores across Scotland. And the union said drivers have voted by 126 to 6 to strike.
Webb said: 'The strike is solid. Our members are in good spirits and the pickets are having some success in turning vehicles round. Tesco is clearly rattled by the way they are trying to place all manner of obstacles in the way of our pickets. But we are determined to expose this company for the arrogant way it has treated its staff, our members, and the union itself.'
He added: 'Extra fencing, extra locks and extra security guards shows just how far this dispute has got to Tesco. We said we'd fight back against the way our members were being treated and that fight has begun.'
The union said Tesco gave Scottish drivers an ultimatum to sign to cuts or be sacked. Drivers at Livingston, near Edinburgh, were told they had to sign up to new working conditions or face losing their jobs, after news that the depot is transferring to a new location 500 yards down the road. According to a T&G spokesman, the dispute is about two main issues: a loss of pay as a result of the move and the loss of union recognition.
Union leaders have told Tesco that the dispute could escalate to a national ballot, as part of their ongoing campaign. Webb said: 'Our shop stewards see the attack on the Scottish drivers as the first shot in a national attack by the company.'