Recruiters have reacted strongly to calls by the construction workers union UCATT that self-employed workers should be banned from working on the London Olympics.

Alan Ritchie, the union's general secretary, claimed using self-employed workers would encourage tax abuses, reduce site safety and deny opportunities for local people.

Simon Gerrard, director at NES, London, said a "uniform approach" was required across the construction industry, rather than one focused purely on the Olympics projects, to ensure that workers' tax and National Insurance (NI) contributions are administered correctly.

"With demand already sky high in London, putting a block on hiring self-employed workers on the Olympics projects would seriously harm the Olympic Delivery Authority's (ODA) chances of delivering the 2012 Games on schedule," said Gerrard. "And to ensure local people benefit, an initiative to hire them for the Olympics projects should be part of the tendering process," he added.

Jason Silk, HR director at Hill McGlynn, said any suggestion that site safety would be reduced was "clearly not the case", adding: "We only supply candidates who are appropriately skilled."

Silk said banning self-employed workers from the Olympics would be unpractical, as well as unfair as they had not broken any tax rules.

"I am not sure [the ODA] could legally do that," he said, adding: "I am not sure how it would work."

But Silk said if UCATT was calling for a review of the tax regulations under which people worked then that was "a different point", and would be a matter for the government.