Waitrose’s Walton-le-Dale store in Preston narrowly edged out Tesco to pick up a second successive store of the week award for the upmarket retailer.

Overall, our mystery shopper had a smooth, hassle-free experience at a store she was familiar with, adding up to a total of 76 points. The car park was a little untidy with some trolleys abandoned rather than being returned to the clearly signposted cleaning shelter. But the store itself was clean and tidy. There was some replenishment taking place but staff were careful to keep their trolleys out of the way and not cause any obstructions.

Staff were generally excellent and proved particularly helpful on the two occasions our shopper asked for help finding a product. Both partners stopped what they were doing and escorted her to the required item. The checkout operator was also friendly and helpful.

In terms of availability there were two out of stock items and two not-stocked lines.

Tesco in Amersham, which picked up 74 points, fared slightly worse on availability, with three out of stocks and three not-stocked items. Beyond that our shopper was full of praise for the store. She was carrying out a first big shop since November as she had been shielding and said she “felt very safe”. This was largely down to the strong Covid security measures in-store which included a traffic light system, separate entrance and exit, good availability of cleaning products for trolleys and plenty of hand sanitiser.

Wide aisles made it easy to maintain social distancing, although this was helped by the store not being busy, and our shopper described staff as “nice, friendly and helpful”. They all checked in the stockroom for missing items or joined our shopper in scanning the shelves for the products that turned out to be not stocked.

Sainsbury’s Selly Oak store in Birmingham scored 65 points. It recorded the joint-best availability with just one product out of stock and two not sold.

The shopping trip did not start or end well for our shopper, however. On entering the car park she observed a number of abandoned trolleys scattered around – while on the way back to her car she found the travelator broken, resulting in a lengthy queue for the lift. She opted to “lug four bags of shopping down the stairs to the car”. In between everything was largely fine, the highlight being the “very helpful staff member” from whom she asked assistance who was “polite and approachable”.

Asda’s Birkenhead store, which scored 61 points, matched Sainsbury’s on availability. But abandoned trolleys in car park spaces was an issue.

Our shopper found staff very helpful but her main source of frustration was a 10-minute wait at the checkout as there were only four checkouts open. She described the checkout experience as “stressful and time-consuming” and said it would put her off shopping with Asda in the future.

Morrisons in Reigate brought up the rear this week, scoring just 46 points. The biggest problem was availability. Our shopper managed to go home with just 24 products due to nine out of stocks.

However, our shopper also found the store layout difficult to navigate. This was not helped by abandoned restocking trolleys in some of the aisles. Our shopper said staff were good but as with Asda, she felt there were not enough tills open which led to a longer than necessary wait at the checkout.