LONDON (AP) — Several British supermarket chains have limited the amount of some fresh fruits and vegetables that customers can buy amid shortages blamed on bad weather in Spain and Morocco.

Tesco, the U.K.’s largest grocery chain, said Wednesday that it would temporarily limit customers to buying three items each of tomatoes, peppers and cucumbers. It follows similar moves by rival chains Aldi and Morrisons.

The empty shelves have become a political issue, with opponents of Britain’s decision to leave the European Union blaming Brexit for the fruit and vegetable shortages.

But industry analysts said the main culprit was bad weather hurting crop yields in Spain and Morocco, two of the U.K.’s main suppliers of fresh produce in the winter.

Spain has had some unusually cold weather, while Morocco also was hit by frosty temperatures in January, followed by canceled ferries due to bad weather over the past month. That meant less produce being shipped to Britain.

Ireland — an EU member but, like Britain, a chilly island that relies on seasonal imports — also has seen shortages of some fresh vegetables.

“Difficult weather conditions in the south of Europe and northern Africa have disrupted the harvest for some fruit and vegetables including tomatoes and peppers,” said Andrew Opie, director of food and sustainability at the British Retail Consortium, which represents U.K. supermarkets.

Opie said disruption was expected to last “a few weeks.”

“Supermarkets are adept at managing supply chain issues and are working with farmers to ensure that customers are able to access a wide range of fresh produce,” he said.