Alcohol companies in a central Chinese province are to challenge a ban on government officials enjoying a drink during their lunch break.

The order was brought in a year ago by the Government to address corruption and improve efficiency among its workers — a task somewhat hindered by the regular practice of employees taking long, alcohol-fuelled lunches. More than 100 officials in Xinyang have been reprimanded for flouting the rule.

Now, producers of baijiu, a clear grain liquor famed for its potency, are complaining that revenues have plunged by as much as a third since the ban came in.

Alcohol producers in Henan province have gone so far as to retain a lawyer whose task is to collect opinions from liquor manufacturers and present his findings to the provincial legislature. The aim is to demand a revision or the lifting of the ban.

Kang Yinzhong, the lawyer hired by the Henan Alcohol Association, argued that drinking was a private matter and even those who held public office should be allowed to sip alcohol at lunch as long as it did not affect their work.

He questioned the legality of the ban, saying: “No government document can sit above the law.”

The most popular liquor manufacturer in the region — Jinguchen, or Golden Green Spring — reported that sales had dropped from 60 million yuan (£4 million) in the first eight months of 2006 to 40 million yuan in the first eight months of last year after the ban took effect.

The Government said that the sobriety campaign had saved it 43 million yuan in the first half of last year alone — enough to build at least 40 primary schools or equivalent to the entire annual revenue of a small county. The number of illnesses linked to excessive drinking had fallen by half.

Drinking in China is as much a show of machismo as enjoyment. Diners challenge one another to empty their glass, which is immediately refilled with another shot of liquor, often about 60 per cent proof. Failure to join in means a loss of face.

Wang Tie, Communist Party chief of Xinyang and the man who initiated the sobriety campaign, said that he stood behind the prohibition, which does not prevent officials from taking a tipple in the evening.

“This has won a warm welcome from the public and we will firmly carry on with it,” he declared.

China's Communist rulers have repeatedly pointed out that rising corruption and lavish displays of wealth and consumption by public servants have aroused widespread public anger and pose one of the greatest threats to the party's grip on power.

The challenge by liquor producers and restaurants over such an emotive issue thus stands scant chance of success.

One law professor said it was hardly surprising that the ban had aroused controversy since it damaged the interests of the alcohol industry.

Times Recommends

• Henning Mankell: ‘If Wallander was alive, I wouldn’t be a friend of his’
• Secret society's skull and crossbones for sale
• Nigerian leader vanishes after medical treatment