Yates Group has been criticised for allowing one of its pubs to trade without any soft drinks.
Its Basingstoke outlet opened on August 14 with no lemonade, cola or soda water. The Saturday night customers could not buy any soft drinks on tap and only a few mixers were available.
Yates blamed the problem on a faulty gas system. But it has been criticised for its policy of preventing staff from buying emergency supplies from a local supermarket.
Vicki McNally, a customer in the pub on the night in question, said: "It was ridiculous - virtually impossible to find any soft drinks. Some people were drinking straight vodka."
Kevin Allcock, operations excellence manager for Yates Group, said: "We don't encourage our bars to pick up bottles and cans from supermarkets because of the quality issue."
He explained that the company has a 24-hour maintenance agreement with its supplier which meant the system could not be fixed until the following day. Yates will be resolving the issue with its supplier.
Bill Sharp, licensee of the Kings Arms in London Bridge and representative of the Guild of Master Victuallers, said: "The trade has got to be seen to be responsible and some people might consider this an irresponsible act. People who are driving might be tempted to have something they consider similar, such as an alcopop.
"In these circumstances common sense should prevail."
Rob Bates, owner and licensee of Rhu-Bar in Basingstoke - which is opposite Yates's - said: "The management should have taken the initiative to go and get some stock in. "The managers have a hard job and have no authority to buy soft drinks. It's all down to head office."