Keller confirmed the charge in a Stock Exchange announcement today as a legal row which started after the warehouse was finished in 2008 rumbles on.

Keller said: “The dispute relates to purported defects in a floor slab at a warehouse for which Keller Limited undertook the design and construction of the piling.

“These purported defects are alleged by other parties to be due, in part at least, to deficiencies in the provision of Keller’s services.

“The claims intimated against Keller Limited, which are currently the subject of litigation, are denied and being vigorously defended.

“However, the Board has determined that, given the uncertainties inherent in any litigation, it would be appropriate to record an exceptional charge of £30 million in the Group’s 2014 half year results.

“The amount is stated before taking account of recoveries under applicable insurances which are yet to be agreed.

“The Group will update the market on future developments when necessary.”

The dispute is believed to involve construction of Europe’s largest wine warehouse in Bristol where VolkerFitzpatrick was main contractor.