Cameron, in a column for the Daily Telegraph, accused recruitment agencies of "recruiting elsewhere in the EU without British workers getting the chance to apply".
Green denied the prime minister's claims. He told HR magazine recruitment agencies have been caught in the middle of a "dogfight" between the main political parties.
"Labour have made similar comments before," he said. "We all know that immigration is a huge issue, especially in employment, but we feel these comments are very, very unhelpful. From the evidence on tribunals we don't see any sign that our members are guilty of this."
Green added that the REC consults regularly with the Department for Business, Innovation & Skills to ensure both sides understand recruitment agencies' requirements to be compliant with legislation and codes of conduct.
In his column, the prime minister also claimed the Government is "banning overseas-only recruitment". Green countered that this is already illegal under the Equality Act, as well as being outlawed for REC members.
"There is already legislation in this area," he continued. "We also have an internal code of conduct that prohibits bad practice like this. If any of our members are found to be doing this we take action. We already have some agencies on official warnings. In extreme cases we can expel them, although this is a last resort."
