Argos and Goldsmiths are falling behind other jewellers in their response to a campaign to change the way gold is mined in developing countries, the Catholic Agency for Overseas Development has warned.

CAFOD's Unearth Justice campaign to reduce the harm caused by gold mining has received the backing of other jewellers including Beaverbrooks, F Hinds and Fraser Hart who have signed up to 12 'Golden Rules' to clean up the gold industry.

Despite a year of campaigning, however, the companies Argos and Goldsmiths are still yet to sign up.

CAFOD is urging thousands of campaigners Thursday to email the chief executives of both companies to call on them to sign up to golden rules that could help to minimise the harm done to communities and the environment.

The aid agency warned that it is difficult at present for jewellers to say with confidence how the gold in their products is mined. If the industry implemented the golden rules this would lead to greater transparency, it claimed.

Helen Wolfson, Head of Campaigns at CAFOD, said: "As industry leaders Argos and Goldsmiths can send a clear message across the industry and the supply chain that gold shouldn't be damaging developing countries.

"Argos and Goldsmiths should listen to the consumers who want them to back this campaign and the mining communities who need them to."

Mining for the gold for one ring can create 18 tonnes of waste - the equivalent of two double-decker buses - that may leach toxic metals and acid, CAFOD warned. CAFOD said it had also found evidence of cyanide and arsenic pollution, people being forced from their homes, and environments being destroyed by large scale gold mining activities.

"Britons spend £2bn on gold jewellery every year and jewellers have an influential role to play in championing the cause of clean gold with the industry," said CAFOD.

A poll carried out on behalf of the charity found that one in four people claimed they would buy Fairtrade gold on sale, even if it meant paying more.

CAFOD is campaigning to highlight the hidden harm caused by gold mining and to get governments and multinational businesses to give poor communities a much greater say in whether gold is mined, how is it mined and who benefits. Already over 100 high street shops have been presented with petitions that include 45,000 signatures calling on jewellers to take action.

The industry standards are based on the No Dirty Gold campaign and the 12 'Golden Rules' include respect for human rights and free, prior and informed consent for affected communities.