Spain temporarily authorised stores on Wednesday to limit the sale of some products to prevent sell-outs when markets are under stress, days after some supermarkets ran out of sunflower oil and milk, reported Reuters.

Supermarkets had been calling for legal backing for such rationing, which was announced by the government as part of an emergency package to mitigate the economic fallout of Russia's invasion of Ukraine and will be in place until 30 June.

The move came after the war in Ukraine and a three-week truckers' strike led to sporadic shortages of staples such as eggs, milk, flour and sunflower oil, though shortages were often caused more by hoarding than by actual supply disruptions.

"It provides legal backing so that they can limit the number of articles and thus avoid hoarding, but above all, so that there is fair access for all consumers," Trade Minister Reyes Maroto told reporters.

Some supermarkets in Greece and Italy have been restricting the quantities customers can buy of some staples after seeing demand rise due to worries the Ukraine conflict could disrupt supplies.

Spanish authorities and supermarket associations warned against panic purchases during a transport strike that started on 14 March. Although one association has not called off the strike yet, it has lost momentum after the government granted a 1 billion euro ($1.10 billion) support package.

Two years ago, as European governments were preparing lockdowns to curb the COVID-19 pandemic, some Spanish supermarkets rationed some products in response to panic-buying of items such as toilet paper, but the government did not sanction it.

Earlier this month, consumer association Facua sued some Spanish supermarkets for breaking the law after they limited the purchase of sunflower oil to a few bottles per person. Ukrainian sunflower oil accounted for 40% of imports.

"We are also responding to a need that the distribution sector has expressed to us and which has become clear with the recent transport strike," Maroto added.

Dairy farmers and industry association Inlac, which stopped production during the strike as milk could not be transported, said on Wednesday they hoped supplies would be back to normal in between three days and a week's time.