Tesco has been awarded the lowest food hygiene score of the major multiples in a new report by The Grocer - but the independent sector fared far, far worse.

Analysis by The Grocer of thousands of food hygiene ratings awarded by local authority food safety officers showed that Tesco was told to improve following 33 (or 3.2%) of the 1,045 inspections carried out since the start of last year.

The 33 stores scored 1 or 2 points - requiring major improvement or improvement necessary respectively - using the new unified food hygiene rating scheme introduced by the FSA in November 2010. Its One Stop convenience chain did even worse, with 5.3% of its stores told to improve.

Out of 2,387 inspections at the five leading supermarket chains, 2.3% needed to improve, according to the data, compiled for The Grocer by Transparency Data.

Food hygiene scores are based on three criteria: how hygienically food is handled the condition of buildings and procedures and record keeping to make sure food is safe.

A Tesco spokeswoman said the scores were not an accurate reflection of its hygiene standards, and was working with the relevant authorities to address “the lack of consistency in inspection ratings”.

“All Tesco stores have systems in place to ensure the highest levels of hygiene. Our stores are independently audited up to four times a year - more often than local authority inspections and more rigorously.”

The best-performing retailer was Waitrose. It scored a five - the highest possible rating - for 92% of inspections, compared with 75.9% across the big five, and 69% for Tesco. “We believe our customers should be able to assume these standards are a given, leaving them to enjoy our food and in-store experience,” said a spokeswoman.

In the meantime, scores for independently owned symbol stores were significantly worse, with 17.1% of the 2,137 inspections at Best One, Mace, Budgens, Londis, Spar and Nisa stores resulting in a score of two or below. And 20 stores scored a zero, meaning urgent improvement was necessary.

The results suggest either “a need for greater awareness about food hygiene rules among the smallest businesses, or food hygiene inspections are focused on documented compliance procedures, an area for which multiples tend to employ specialists,” said ACS CEO James Lowman.

An FSA spokeswoman insisted the scheme was designed so any business could achieve a top score. “It’s just a case of complying with hygiene regulations,” she said.

Licking chicken and munching mice: the retailers’ horrible histories

January 2010: Asda shelf stacker Adeel Ayub was jailed for two months after YouTube footage was posted on the internet showing him licking raw chicken before placing it back on the shelf.

March 2012: Rampaging rodents forced the closure of Tesco’s flagship Covent Garden Metro store. Tesco carried out a total refurbishment of the store, closing it for several weeks.

June 2012: Sainsbury’s closed its store in Westbourne Grove, Bayswater, for more than a week after a mouse infestation. An “emergency prohibition notice” told customers it was closed.

June 2012: Poundland was fined £24,000 for a string of offences after staff at a store in Croydon’s Whitgift Centre were found to have resealed packets of biscuits after they were gnawed by mice.