In an internal newsletter, OFSTED’s head of contracts, Clive Bramley, says that he was alarmed to see a recent advertisement in The TES from a company urgently seeking inspectors to work this term. He suggests that if companies are racing around trying to recruit inspectors at the last minute, the quality of the inspections will suffer.

He writes: “I do expect contractors to be clear how they plan to meet their contractual obligations with us. In plain language, I will not look kindly upon those who make commitments with us without adequate planning. To do otherwise would be to bring into question their quality assurance arrangements.”

The warning comes two weeks after the contracts of hundreds of heads and deputies recruited as additional inspectors were terminated by OFSTED because the shortage of primary inspectors was said to be over.

One OFSTED source said that the problem was “the tip of the iceberg - a big crisis could be approaching. He (Mr Bramley) would not have bothered to say this in the newsletter if it had been a question of one advert; there are a number of contractors struggling to make up teams and they are having to put in some dicey members”. He also said that local authorities were pulling out of inspection because of the cost.

The advertisement referred to by Mr Bramley was placed in The TES on January 31 by City Inspectors Services, of south London. It states that the company urgently requires freelance lead inspectors (RgIs), and team members for primary inspections for the spring, summer and autumn terms. Nobody at CIS was available for comment this week.

However, Ron Elam, a lay inspector who has secured work with CIS next term, said he was surprised by the wording of the advertisement.

“Contractors often miscalculate the number of people they need, but it’s usually two or three people,” he said. his advert gave the impression they were very short.

“When I phoned them, they were working flat out trying to find inspectors to do immediate work.”

He also said that CIS was offering lower wages than average (Pounds 150 a day compared with the norm of around Pounds 200), “which suggests that they might have won the contract because they put in a very low bid”.

Mr Elam also said he had complained to OFSTED about another advertisement recruiting inspectors to work “within the M25 area”, placed by a company named Claremont and Crizzle, which turned out to be operating from Portugal. He said that OFSTED had told him that the company was not registered or approved by OFSTED.

Ceridwen Clarke, contracts manager for OFSTED, told The TES that Claremont and Crizzle was acting as a “dating agency” - matching up inspectors with contractors and although this was acceptable, she admitted that OFSTED was concerned about the implications of the CIS advert.

“It does look as if they are recruiting people at the last minute. We’re clearly not happy, as this is not how we want to see work being carried out. It raises questions about quality,” she said.

Ted Wragg, professor of education at Exeter University and a vociferous critic of the OFSTED system, said: “Because inspection is now run as a profit-making business rather than a public service, these sort of commercial problems are bound to occur - people are scrabbling around to recruit labour and being forced to put in low bids, putting quality at risk.”