Distribution staff at supermarket group ASDA have turned down what union leaders have described as a "real terms pay cut", with a large majority said to be prepared to go on strike.

Almost 70 per cent of the 8,000 GMB members polled turned down the pay offer, the union said, while nearly 80% of warehouse, clerical workers and LGV drivers said they were ready to take industrial action over pay.

In an offer to staff last months, Asda proposed increased of between 4.98 and 6.1 per cent for warehouse and clerical staff, averaging out to an increase of 5.53%, and between 6.49% and 7.53% for transport staff, an average of 7.02%. Specific increases depend on location, role and grade.

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Inflation as measured by the UK's consumer price index (CPI) hit a 30-year high of 5.5% in January, while on the old all-items retail prices index (RPI) measure it surged from 7.5% to 7.8%. The Bank of England has predicted that CPI inflation will peak at 7.25% in April.

As part of a national recognition agreement signed by Asda and the GMB in 2012, the two sides are required to hold further meetings, including talks with arbitration group ACAS, in an attempt to resolve their differences without resort to industrial action.

Nadine Houghton, national officer at the GMB, said the union will now meet with members to discuss their next steps.

“The UK is facing the worst cost of living crisis for a generation," she said. “Inflation is rampant and energy prices are out of control. 

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“Yet Asda workers are being taken for mugs with below inflation pay offer that basically means a real terms pay cut. 

"They’re not going to take it lying down – it's now up to Asda bosses to come back with a reasonable offer and avert the threat of industrial action.”

The disapute with drivers and warehouse workers kicked off in December, with ASDA accusing the GMB of going far above and beyond a pay deal agreed earlier this year. That two-year agreement, signed in May, included an offer of a £1,000 one-off retention payment to existing HGV drivers. 

Speaking yesterday, Asda's vice president of logistics Jon Parry said: “We value the key role our colleagues play to keep our stores well stocked and we have negotiated in good faith with the GMB to make a fair, competitive and sustainable pay offer that recognises rising inflation.

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"We are disappointed this has been rejected and we expect the GMB to honour the National Recognition Agreement, signed by both parties in 2012, as this provides an agreed framework to resolve outstanding matters.”    

The dispute is being watched closely across the industry as unions entered into negotiations with many of big food companies from the start of this year.

GMB and Asda are also in a long-running equal pay dispute on behalf of 40,000 Asda shopworkers. It relates to whether the role of store staff, who are predominantly women, can be compared with distribution workers for pay purposes.