Local councils are spending millions of pounds performing criminal background checks on everyone from tree surgeons to burger van sellers, it has been claimed, despite promises from the government to scale back the CRB system.

According to a report by the Manifesto Club, 490 councils across England and Wales carried out nearly one million CRB checks in a single year, with the rate of checks increasing by 51 per cent since 2004-2005.

The report said some councils were checking thousands of volunteers and that local authorities were “over-vetting” and “wasting millions on unnecessary CRB checks” when frontline services were being cutback due to strained finances.

In the highest checking authorities, CRB checks were said to have been carried out on parent volunteers, arboreal assistants, burger van sellers, art therapists, countryside wardens, sewage pump engineers and foreign exchange hosts.

Hertfordshire County Council was identified as having the highest rate of checks, with 21,680 carried out in 2010-2011. And this was closely followed by Essex at 21,610 and Devon at 20,095.

David Lloyd, Hertfordshire’s cabinet member for resources and economic wellbeing said the council applied a “safe staffing policy” to all employees and that it worked closely with the CRB.

“Hertfordshire is a densely populated county with over a million residents,” he said. “The county council employs around 30,000 people, which includes all the staff for over 500 schools. The county council carried out approximately 18,000 CRB checks in 2011 – a reduction from 25,000 in 2010. This reflects how we have taken on board the new guidelines from the CRB.”

A spokesman for Essex County Council added: “Being a registered CRB umbrella organisation, Essex County Council undertakes CRB checks for many organisations and services such as other public sector organisations, charities, social care providers and schools.”

And a Devon County Council spokesman said they took safety and welfare “extremely seriously”. “As part of that we have to ensure that the right checks are carried out prior to filling certain posts,” he said. “Devon’s figure is proportionally higher because we act as an umbrella agency and provide the service for a number of organisations such as charities, external companies, schools, academies, and district councils.”

The total cost of local authority CRB checks since 2004 was nevertheless said to stand at more than £284m.

This follows news from just days ago that nearly three million CRB checks had been carried out in 2011, the equivalent of one in 17 of the country’s adult population.

At the time a spokesman for the Home Office said the current system of employment checks was “too bureaucratic and intrusive”.

“That is why we are reforming the regime to scale it back to common sense levels so that the public are properly protected but the number of excessive checks are substantially reduced,” he said.