Construction workers demonstrated outside the headquarters of an international employment agency yesterday after the firm was accused of being involved in blacklisting.

Atlanco Rimec’s British division is based in Northampton.

The firm also operates in Denmark, the Netherlands, Sweden, Ireland, France, Poland, Norway and Australia. It has thousands of construction workers on its books.

Yesterday’s demonstration was organised by construction union Ucatt. It followed a Danish TV probe which accused Atlanco Rimec of operating a blacklisting policy against union activists.

The firm is also accused of shoddy treatment of immigrant construction workers. The European Federation of Construction Unions (EFBWW) said the firm charged Portuguese workers in the

Netherlands €968 (£773) a month for “logistical costs” but housed them in cheap accommodation rented at a fraction of the charge.

Ucatt general secretary Steve Murphy said: “Ucatt members are angry that a company that operates in Britain is allegedly involved in blacklisting and mistreating construction workers. It is clear that blacklisting is continuing to occur in construction and it must be stamped out once and for all.”

Ucatt Midlands regional secretary Cheryl Pidgeon said: “Atlanco Rimec employs thousands of construction workers. Workers who have sought employment with them have the right to know whether they have been secretly blacklisted.”

On Tuesday next week Michael Collins appears in Manchester Crown Court charged with dangerous driving in relation to an incident which left anti-blacklisting campaigner and Unite member George Tapp with two broken legs and a fractured skull.