Food shoppers in Northern Ireland will be the first to pay the 5p levy introduced on plastic bags in Marks and Spencer's UK stores from July.
The retailer today began a trial scheme that will see customers charged for carrier bags.
During June, customers will be offered free "Bags for Life" with every food transaction; in July, customers will have to pay for their plastic carriers.
It was reported this morning that the trial could then be rolled out to the rest of the United Kingdom.
The move comes as part of M&S's drive, called "Plan A", towards ethical trading and the promotion of healthy lifestyles. The five-year scheme aims to see M&S become carbon neutral, stop sending waste to landfill and extend its sustainable sourcing by 2012.
The group also announced that, in partnership with its suppliers, it will develop two "eco-factories" to pioneer methods of sustainable manufacturing.