Asda is to roll out the country's first ecological egg to all its English and Welsh stores.

From Monday (11 June), branded Respectful Eggs from a handful of low-carbon farms in Lincolnshire will go on sale in 280 Asda stores. It follows a successful seven-month trial in 60 Asda stores, which sold around 3,600 packs a week.

The eggs get to stores with half the carbon footprint of standard free-range eggs, and Respectful claims buying them for a year can help the average egg consumer trim 0.2% off their greenhouse gas emissions.

Power on the farms comes from wind turbines and solar panels, waste is recycled into fertiliser, and the egg boxes are made of recycled paper pulp.

The eggs go on sale at £1.05 for half a dozen - broadly comparable to other free-range eggs.

Respectful supplier Stonegate is increasing the number of low-carbon flocks it buys eggs from. By 2008 it will be able to cover 10% of Asda's free-range requirement with Respectful eggs.