Both sides of the pubco debate have about eight weeks to make their cases to Europe as it re-examines the beer tie.
The European front in the beer tie battle has opened with the publication of the consultation on the exemption for the beer tie under European competition law.
The Block Exemption Regulations (BER) grant some commercial agreements, including the beer tie, exemption from Article 81 of the EC Treaty, which outlaws agreements that prevent competition.
The BER expire on 31 May 2010 and a draft consultation into exemptions has now been published.
The EU will consider whether the status quo is anti-competitive, particularly if it denies producers access to market.
The anti-beer tie coalition Fair Pint, the Federation of Small Businesses and the GMB Union is expected to use the consultation to argue for the tie to be outlawed.
Campaign for Real Ale director of public affairs Jonathan Mail said it would be responding, although it wants the beer tie to remain in place for family brewers.
"We argued in our super complaint to the Office of Fair Trading that some practices are anti-competitive and should be lifted," he said.
Robert Humphreys, secretary of the All-Party Parliamentary Beer Group at Westminster and its sister group in the European Parliament, said: "A lot will depend on how the market is defined. For example, do you include the off-trade, and whether the beer tie means there is foreclosure to the UK beer market for brewers from other member states?"
Interested parties have until 28 September 2009 to respond.
• You can view the consultation here.