Asda has unveiled a major shake-up of store operations, which will put close to 300 roles at risk and reduce pay for more than 4,000 night workers.

The supermarket chain has proposed that some overnight restocking shifts at 184 stores are moved to the daytime, putting 211 night shift manager roles at risk.

It said the changes will also affect 4,137 hourly-paid workers, who will see shift patterns move to the daytime and lose their night shift pay premium of at least £2.52 per hour.

The move will affect workers who currently restock ambient products, such as pasta and tinned goods, and staff restocking frozen food.

Asda also revealed it will reduce staff hours by 22% across all the group’s 23 in-store Post Office shops, with four reducing their opening hours as a result.

It said the four stores will see their hours reduced by roughly 9%.

The changes at in-store branches – which employ 23 managers and 200 other workers – come after “a decline in the number of customers using this service”, the retailer said.

Meanwhile, it will also shut seven in-store pharmacies, which employ 14 pharmacists and 48 other workers.

The closure of these pharmacies comes weeks after LloydsPharmacy said it will pull out of its 237 pharmacy sites within Sainsbury’s supermarkets.

Asda’s retail director, Ken Towle, said: “The retail sector is evolving at pace and it is vital we review changing customer preferences, along with our own ways of working, to ensure we are operating as efficiently as possible so that we can continue to invest and grow our business.

“We are now entering a period of consultation with our colleagues on these proposals.

“We recognise this will be a difficult time for them and will do all we can to support them through this process.”

The shake-up comes two years after the company was snapped up by the billionaire Issa brothers and private equity backers TDR Capital for around £6.8 billion.