Public health is being put at risk because councils are failing to carry out the required number of inspections at restaurants, takeaways and food processing plants, a report by the Food Standards Agency claims.

This is despite heightened concerns about food quality and standards following the horsemeat scandal and revelations about the potentially lethal food-poisoning bug campylobacter in supermarket chickens.

The report, which has tracked trends in enforcement activity over the past five years, found that many local authorities are failing to meet their obligations under UK law. Between 2010 and 2015, while there was growth of almost 7% in the number of UK food businesses, there was a similar fall in “food hygiene interventions” – inspections into the quality and contamination of food.

The number of food standards interventions, which examine whether food has been adulterated or mislabelled, fell by 6% over the same period.

“The overall position is one of growing concern,” the report notes, warning that there is worse to come. “At a local level, there are a good number of authorities which are struggling to undertake interventions of food businesses at the required frequencies. More generally, the number of food businesses and customer complaints continue to rise, while local authority staff resources, intervention and sampling levels continue to fall.

“These trends … highlight that many are not able to deliver a food service as set out in the statutory food law code of practice. We are also acutely aware that local authority resources, particularly in England, will face further significant reductions over the next few years.”

Anne Godfrey, the new chief executive of the Chartered Institute of Environmental Health, warned that trust in the UK’s multibillion pound food manufacturing and hospitality sectors was in danger of being undermined.

“Going out to eat should be an enjoyable experience and consumers should expect that the food they are eating is safe,” Godfrey said. “Food inspections and sampling are important checks, forming the basis of the food hygiene ratings scores, which are designed to provide robust information as well as allowing consumers to know exactly what the inspector has found. If the system fails in places, then the risks to people’s health and wellbeing are likely to increase.”

One particular concern is the steep drop in the random sampling of food, which has occurred despite calls for more testing of products in the wake of the horsemeat scandal. The report states: “The number of UK official samples has followed a steep downward trend (apart from a small increase in 2013-14, which was likely the result of increased activity relating to the horsemeat incident) from 92,122 samples in 2010-11 to 68,471 samples in 2014-15. This equates to a reduction of 25.7%.”

Analysis by Environmental Health News, the trade magazine for health inspectors, reveals that seven councils are carrying out less than 80% of the required interventions. The decline in interventions may be attributed in part to a 17% fall in the numbers of environmental health inspectors, from 2,775 in 2010 to 2,303 last year.

In a letter to the chancellor, George Osborne, several leading food safety experts, including Professor Chris Elliott, the man who led the official review into the UK’s food supply chain following the horsemeat controversy, warn that “the regulatory system is under tremendous pressure as a result of increasing demands, such as the need to effectively address food fraud and the continuing public sector cuts”.

They note that since 2013, the year of the horsemeat crisis, the FSA has been asked to make £22m in savings, while councils are having to cut their environmental health budgets by about 20%. With further cuts to come, they warn that public health could be jeopardised.

“It is our view that such further budget cuts will decrease the effectiveness and resilience of the regulatory system, reduce consumer confidence in its ability to protect their health and risk undermining trust in the food safety standards of the UK food industry.”