Pubs and pubcos may lose the right to employ overseas staff as they have yet to meet government regulations which come into force in a few weeks' time.
New rules set by the UK Borders Agency are due to come into force in late November.
They state that employers must apply for special status as 'sponsors' before they can employ migrant labour above a certain grade.
The rules affect supervisory and skilled staff and above - such kitchen managers and sous chefs.
Recruitment consultant Nigel Sapsed has been urging pubco clients to ensure they apply for sponsor status "as soon as possible".
He said: "Overseas staff make a vital contribution to the modern British pub and its ability to meet a varied range of customer tastes.
"Yet pubs may lose the right to employ such people unless they can meet the new rules and do so urgently."
Only one UK pub restaurant company - Hall & Woodhouse - appears on the UK Borders Agency's Register of Sponsors.
Hall & Woodhouse, Head of human resources, Sue Hodder, said: "Migrant labour has made a huge contribution to our business over the past six years or so and we have successfully applied for sponsor status to allow us to continue to provide the best service possible to our customers."
She said the new rules were "fairly straightforward" so long as "good employment practices and processes were in place.
For details of how to apply for Sponsor status, visit the UK Border Agency website at www.ukba.homeoffice.gov.uk