Hundreds of publicans have been given the green light to press for damages against Nomura-owned Inntrepreneur Pub Company.
Several hundred former lessees are claiming that Inntrepreneur and Courage put them out of business by demanding high rents and higher prices for beer than they would have paid on the open market.
Inntrepreneur continues to deny the claims, but former Inntrepreneur licensee Bernie Crehan has just won a test case against the pub company and Courage in the European Court of Justice.
Trade experts insist that the European Court of Justice decision now paves the way for publicans to seek millions of pounds in compensation.
Alan Temple (pictured) was head of the Courage Leaseholders' Association when members started to complain that the beer tie agreements were losing them business.
He told thePublican.com that the decision was the right one. "The agreement saw thousands of licensees go out of business at a rate of about 10 per cent a year," he said.
"The European ruling says that the injured party, in this case the lessees, can sue for damages. This could amount to millions of pounds."
Rupert Croft, litigation partner at Charles Russell, the law firm acting for Mr Crehan, said: "This marks a fundamental shift in both UK and European competition law.
"It now means that, as in the US, innocent parties to illegal agreements will be able to recover damages."
But Inntrepreneur director Colin Redford said former tenants would be lucky to secure damages. "The chance of any former tenant receiving damages against Inntrepreneur remains remote," Mr Redford said.
"They may have been given the green light to press for damages but they have still got a steep hill to climb," he added.
Meanwhile, property expert Howard Day is encouraging tenants who think they may be affected to seek professional advice.
He said: "The impact of this judgement will have to be tested in UK courts. But it seems likely that where a landlord imposes terms on a tenant under a tied lease, the landlord is at risk of being sued for damages."