Trendy tonic water brand Fever-Tree has been hit by glass and labour shortages that have jacked up shipping costs to the US.

The London-based company said it is experiencing an "exceptionally challenging environment" as a lack of workers in the US has forced it to make and ship more drinks from the UK amid rising freight costs. The availability of glass is also "severely restricted".

The update covering the six months to June 30 drove shares in Fever-Tree nearly 28 per cent lower in yesterday's trading, down 332.5p at 866.5p. That was despite a 14% increase in sales to £161m.

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"Whilst we are seeing positive top-line performance and expect to deliver good revenue growth for the full year, the challenging logistical and cost headwinds we highlighted previously have significantly worsened in recent months and we now expect them to notably impact our full year margins," chief executive Tim Warrillow said.

"The business is working on a large number of initiatives, and more closely than ever with suppliers throughout our supply chain, to mitigate the transitory headwinds and at the same time ensure we can satisfy the strong demand we are seeing in our growth regions."