Tetley has teamed up with Facebook to allow shoppers to communicate directly with tea growers in Malawi as it seeks to boost its ethical credentials.

Tea farmers and estate workers will use phones and cameras provided by Tetley. The move is part of the brand's Farmers First Hand initiative, enabling consumers to track the estate's journey towards Rainforest Alliance certified status, which offers farms a way of distinguishing products as being socially, economically and environmentally sustainable.

The initiative will initially feature the Lujeri estate in Malawi before expanding to tea estates in other countries.

"We want Tetley tea drinkers to know that they have helped to protect the environment on tea estates and provide sustainable livelihoods for the people there," said Tetley global marketing manager Lucy Denny.