Tesco will today face protests from trade union Unite over its treatment of migrant workers in its meat and poultry supply chain.

The union will argue that practices at its meat suppliers fail to meet Tesco's ethical standards as it claims migrant workers are paid less than permanent, often indigenous employees, at the retailer's AGM in Glasgow today.

Unite said it would mark the first time a British trade union has staged a resolution at a UK company's AGM.

Tesco said its guidelines for suppliers went beyond legal requirements to ensure all workers were treated fairly and without discrimination.

"Tesco already has a strong and proactive approach to managing corporate responsibility and ethical issues throughout our business and supply chain," a spokesman said.