Shortages of courgettes in the wake of bad weather in Spain cost UK supermarkets more than £2m in sales last month.

Year-on-year value sales of the vegetable in the big four plus Waitrose, the Co-op, M&S, Iceland and Ocado was down 51% for the week ending 21 January, according to data from IRI.

Sales fell further the following week, by 58%, representing a slump of £715,000 compared with the same period last year, IRI said.

“We know there have been production problems in Southern Europe and it’s starting to impact sales quite dramatically at the leading grocery multiples,” said IRI head of strategic insight for retail Martin Wood.

“It remains to be seen if this downward trend continues. In the meantime, retailers are having to react quickly to the shortage and look to alternative suppliers to plug the gaps and keep customers happy,” he added.

Meanwhile, the supply shortages - caused by record rainfall in the Murcia region of Spain - meant some 759,000 fewer shoppers bought courgettes during the whole of January, according to data from Kantar Worldpanel.

This represented a 31% drop year on year, while sales of spinach - which has also been heavily affected by poor weather in Spain - was down 12%.

“It’s clear that the poor weather in southern Europe has had a tangible impact on British shopping baskets,” said Kantar’s head of consumer insight Fraser McKevitt.

Suppliers have warned that courgette shortages in UK supermarkets could continue until May. It comes as supermarkets have begun rationing sales of products such as lettuce and broccoli to deter bulk buyers and to protect existing supplies.