Retailers are having to absorb lower margins on lemons after frost hit the Argentinian crop.

The South American country's lemon exports to the UK were only half last year's 6,000 punnets, according to Manuela Leyba, regional export manager for producer San Miguel. Frosts hit the Tucumán growing region, compounding an already depleted crop.

Exporters had asked European supermarkets for higher prices, with the German hard discounters doubling shelf prices.

Discussions had also been held with UK retailers, but according to The Grocer 33 index prices are so far unchanged.

Supplies are expected to remain tight until new season Turkish and Cypriot fruit arrives in the UK in September.

Meanwhile M&S has launched a South African Baby Lemon, said to be the smallest sold at UK retail.