A supermarket cashier sacked for allegedly stealing 1.30 ($3.25) from her employer after more than 30 years' service is at the centre of a heated political row about the excesses of capitalism that threaten to spill into Germany's general election.

Barbara Emme, 50, worked for 31 years as a cashier at a branch of the giant Kaisers supermarket chain in Berlin. But, this week, a labour court upheld her employer's decision to sack her for the suspected theft of 1.30 of bottle deposits.

Yesterday, in what appeared to be the opening salvo in his party's general election campaign, Wolfgang Thierse, a veteran Social Democrat politician and the parliamentary Speaker, seized on the court's decision and condemned it as "antisocial" and as an example of "barbaric" capitalism. "It is cases like these that destroy people's confidence in democracy," Thierse said.

"The court could have decided otherwise and taken into account that she had worked herself to the bone for 31 years for the company."

Horst Seehofer, the leader of the Bavarian conservatives, a sister party to Chancellor Angela Merkel's ruling Christian Democrats, used the case to respond to public anger about the role of banks in the financial crisis.

"I don't understand how a cashier can be fired because of 1.30, while managers who lose billions of euros are allowed to keep their jobs," he said.

The Left party said the court's decision was dominated by an "uncharitable attitude" and that it had "completely ignored the existential needs of an employee".

Emme's case has also become a cause celebre for the trade unions.

The outcry has been accompanied by headlines in the popular press taking the banks to task. The front page of the mass-circulation Bild newspaper proclaimed, "This is how the banks rip off low-income earners", and attacked banks for their interest policies.

Lawyers for Kaisers told the court Emme had been given the chance to come clean after she was turned in by a colleague. They said she could have been given her job back.

Instead, she had blamed others for cashing in the bottle deposits and accused the company of victimising her for her trade-union activities.

Kaisers admitted it had no proof that she stole the cash. But a company spokesman said they had lost confidence in her trustworthiness.

Emme has pledged to take her case to the European Court of Human Rights if necessary.