THE PROPOSED merger between supermarket chains Sainsbury’s and Asda has been referred for a full Competition & Markets Authority (CMA) investigation so the watchdog can determine whether the deal would leave customers in “hundreds of local areas” facing higher costs and poorer service.

The CMA began gathering information on the deal after it was announced at the end of April and launched a formal investigation in August.

Having concluded the first phase of that, the watchdog said that as the proposal “raises sufficient concerns” it is being referred for a more in-depth review.

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“The companies are two of the largest grocery retailers in the UK and their stores overlap in hundreds of local areas, where shoppers could face higher prices or a worse quality of service,” the CMA said.

“These concerns will be considered further in the phase two investigation, along with other issues raised so far with the CMA, including those relating to fuel, general merchandise such as clothing and increased buyer power over suppliers.”

J Sainsbury chief executive Mike Coupe and Asda chief executive Roger Burnley released a joint statement saying they expected the in-depth review to take place and that they “look forward to engaging with the CMA and panel on this next phase of the process”.

The investigation was welcomed by the Federation of Small Businesses, with chairman Mike Cherry saying it is right to identify the impact the deal could have on suppliers.

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“It is vital that the executives at the very top of the two supermarkets can explain how the merger can take place without giving the merged chain increased buyer power over suppliers which would negatively impact the smaller firms in their supply chains,” he said.

“We would hope that this investigation by the CMA will be able to produce cast-iron guarantees that there will be a positive relationship with small suppliers.”

However, Russ Mould of investment firm AJ Bell warned that the outcome of the investigation could prove so onerous that it would negate the benefits of joining forces in the first place.

“Ultimately the risk is the combination could be blocked or given the go ahead with such onerous conditions, such as selling lots of stores for example, that it would begin to undermine the whole rationale for the merger,” he said.

The CMA, which will be consulting with customers, rival retailers, suppliers and industry groups, will issue its final report on the deal in March 2019.

Meanwhile Tesco, whose March 2018 acquisition of wholesaler Booker was also the subject of a full CMA investigation, has launched into the budget space in a bid to beat off competition from low-cost German retailers Aldi and Lidl.

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Tesco chief executive Dave Lewis said that the Jack’s chain, which is named after Tesco founder Jack Cohen, will offer customers “great tasting food at the lowest possible prices”.

The first two Jack’s stores have launched in Chatteris in Cambridgeshire and Immingham in Lincolnshire, with a total of between 10 and 15 expected to open across the UK in the next six months.

Tesco’s £3.7 billion acquisition of wholesaler Booker went live earlier this year after being cleared by the CMA last December.