UK retailers are being urged to get involved in a new ­initiative to lessen the environmental impact of the Costa Rican pineapple trade and improve conditions for local workers.

The Costa Rican government launched a responsible trading initiative this week with a view to boosting the industry's image. It comes after pineapple sales in the UK declined 9% over the past 12 months and follows national media allegations of worker exploitation and ­environmental damage last October.

Four out of five fresh pineapples sold in the UK come from Costa Rica, but in the year to 12 June just 59.4 million kg of fresh, ­unprepared pineapples were sold in the UK, down 9.1% year-on-year [Kantar Worldpanel].

The new initiative known as the National Platform for Responsible Pineapple Production and Trade in Costa Rica was seeking to develop a model and a strategy for responsible production, the Costa Rican government said.

All parts of the pineapple supply chain including UK retailers are being ­encouraged to get involved in the initiative.

Alistair Smith of Banana Link, which campaigns for fair standards in production and trade of bananas and other exotics, said many UK consumers were aware the situation in Costa Rica was "far from satisfactory". The initiative was therefore "a real opportunity for retailers here to engage with a much-needed process of ­dialogue on how improvements in labour conditions and environmental impacts can be achieved", he added.

Last year, a report in The Guardian claimed cheap pineapples on supermarket shelves came at a price of "environmental degradation" and "worker exploitation" on plantations in Costa Rica. It also alleged the industry was making excessive use of pesticides and other chemicals.

The new trading initiative would seek to guarantee good agricultural practices and improved compliance with production standards by the pineapple trade, the Costa Rican ­government said.