In the past year, three in every 10 inspections found failures to comply with public health laws, twice as many as the government's target maximum failure rate.

The result – the worst the Health Directorate has reported – included inspections of other types of premises, such as pharmacies, but the government said most failures related to unsafe food practices.

It was the fifth consecutive year in which inspection pass rates fell well below the official target of 85 per cent.

However, industry group Restaurants and Catering Australia says the result shows that inspections are now tougher, not that hygiene practices are worse.

Its chief executive, John Hart, said the ACT's worst food-poisoning cases had involved raw-egg products, such as mayonnaise, which inspections would not have prevented.

Assistant Health Minister Meegan Fitzharris's spokeswoman said some failures were for "smaller things, like a battery not in a thermometer". Only "a relatively small number" had been significant enough to force the closure of an eatery, the spokeswoman said.

The government pledged five years ago to crack down on unhygienic restaurants in the wake of Canberra Times reports on laws that prevented dirty eateries from being identified.

However, few changes have been introduced since, other than new requirements for staff training and a register of convictions for the most serious food-safety breaches.

The register lists very few breaches and only identifies the businesses years after an offence, often after the eatery closes or has new owners.

The now-closed Copa Brazilian restaurant in Dickson, for example, where a salmonella outbreak poisoned more than 160 people three years ago, was never listed on the register, as the matter remains before court.

By contrast, several jurisdictions internationally, including British councils, publish all health inspection reports.

Government-commissioned polling in 2014 found four in five Canberrans wanted restaurants to display hygiene ratings, known as "scores on doors", that showed the results of health checks.

Then chief minister Katy Gallagher said the public response was "really strong" and she hoped businesses would understand the benefits of the ratings, which are used in parts of Queensland and NSW, including Queanbeyan.

However, industry groups – such as the hotels association, ClubsACT and the food and grocery council – opposed the policy and the government abandoned the idea last year. Labor and the Greens had voiced support for the scheme before the 2012 election, while the Liberals had questioned the need for it.

Mr Hart, of Restaurants and Catering Australia, said the past year's poor compliance result was simply the result of tougher inspections following high-profile salmonella outbreaks in recent years, such as at The Copa.

"They're certainly going to much greater lengths to determine compliance. And I think this [latest result] reflects not a decrease in the standards of food safety but an increase in the penetration of the assessment," he said.

"So we're in fact not getting worse; we're just seeing more technical breaches being considered a non-compliance."

Ms Fitzharris's spokeswoman said the Health Protection Service had tried to improve food safety by developing a manual for its inspectors and a self-audit tool for businesses. It also set up a reference group in 2014 to collaborate with industry and public health groups, she said.

However, Opposition Leader Jeremy Hanson said the government had been obsessed with increasing regulation instead of enforcing existing laws.

He cited a "scathing" 2011 Auditor-General's report on food safety, which found flaws in the way the Health Protection Service managed inspections.

Mr Hanson said the latest data suggested that, "once again, the regime is failing".

"The vast majority of food outlets in Canberra do the right thing. However, there will always be those that don't and the focus should be on those who are not complying," he said.

"I have no confidence that the government would be able to implement and monitor such a regime effectively."

A KPMG analysis of food-safety policies, published in 2012, suggested 60 to 80 per cent of food-borne illnesses were the result of meals bought at eateries.

It estimated that these food-poisoning cases cost the ACT economy between $61 million and $89 million a year, through pain and suffering, food recall and compensation costs, and productivity losses.