Exploited workers at a Marks & Spencer distribution depot have voted overwhelmingly in favour of recognition of their union, GMB.

The union ballot won on a 76 per cent turnout with 97 per cent in favour of representation by GMB.

Staff are employed using the “umbrella company” system involving agencies and contractors falsely employing staff as self-employed, meaning they pay the employer’s national insurance as well as their own.

GMB organiser Carole Vallelly condemned the use of zero-hours contracts. She said: “It is a scandal that a company like Marks & Spencer, who boast about their ethical credentials, are exploiting workers in conditions akin to modern day-slavery.”

The Swindon staff are fighting back with a demonstration on Friday.

Ms Vallelly said: “GMB’s next step will be to submit a pay claim for GMB members and secure for them a wage that allows them to live with dignity.”