The RHA lead price-fixing compensation action has attracted more than 2,000 hauliers since it went live in June of this year.
According to the association, which is working on the claim before the Competition Appeal Tribunal in London with legal counsel Backhouse Jones and Exchange Chambers, 650 other hauliers have expressed an interest.
The RHA, which has funding from Therium for the legal action, claimed those already signed up represented circa 120,000 vehicles at 6-tonnes up purchased during the cartel period (1997 to 2011).