The group pointed out that EU nationals represent 7% of the entire UK labour force, while in London that percentage rises to 17%.
The financial and business service sector is the largest employer of EU nationals in London, REC said, with 191,400 employees, or 16% of the workforce.
This is followed by a third of the construction workers and a fifth of retail and hospitality workers, at 33% and 21% respectively.
Kevin Green, REC’s chief executive, said, “Decisions about the future immigration system are too important to be subject to political whim - we need policy to be built on sound evidence and data.
“Designing the post-Brexit immigration system is an enormous task and it cannot happen only in Whitehall. Recruiters are on the frontline of the labour market, and we are ready to work with the government to design and deliver policies that will help the country prosper.”
The REC urged the government to grant greater independence and autonomy to its Migration Committee, develop a five-year road map for the implementation of a new immigration policy and build a visa system that reflects the UK’s dependency on workers from the EU.
On Monday, the government published a 15-page document outlining the detail of the UK’s offer to the three million EU citizens living in Britain.
Theresa May’s proposals on the rights of European citizens living and working in the UK have won support from some business organisations, but have also been met with trepidation by others, who argued that “substantial questions” remain unanswered.