Unilever, which owns PG Tips, has supported the industry-run Ethical Tea Partnership for several years but until now have not promoted its involvement to consumers by displaying the logo on its products.
Members of the ETP, which include Tetley, Sara Lee, Twinings and Unilever, are planning an on-pack campaign this spring to advertise the industry's social responsibility efforts.
The campaign will encourage consumers to go to the ETP website, where they will find details of the partnership's attempts to ensure compliance with local laws and national union agreements on workers' rights and environmental protection.
The ETP, launched in 1997, expects that every tea-producing country will be covered by the partnership's monitoring programme by 2008. Until now, only some members of the ETP have displayed the scheme on their packaging.
Katy Tubb, ETP chairman, said: "This is not a certification scheme. Instead we are inviting consumers to join us in working for a responsible tea industry."
The ETP is different to the most well-known ethical trading certification scheme, the Fairtrade Foundation, which covers industries such as tea, coffee and chocolate.
The ETP has been criticised by rival ethical trading schemes such as Cafedirect for not matching its commitment to guarantee minimum prices paid to producers.
The official Fairtrade mark requires all coffee producers to be organised into co-operatives or similar associations, something manufacturers in the ETP scheme are not required to do.
Spending on Fairtrade and organic items as well as free-range eggs and meats, rose from £3.7bn to £4.1bn according to the Co-operative Bank's annual Ethical Consumerism report published last December.
The tea industry has been signing up tea growers around the world to the ETP and has recently made inroads into southern India and China, two of the largest tea-growing regions. Monitoring in South America began last year.
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