The Circle K and 7-Eleven chains have been warned they could face a boycott after saying they were considering giving customers free paper bags when the 50-cent plastic bag levy comes into force on July 7. The warning came after Secretary for the Environment Edward Yau Tang-wah said last week that the government would write to the two convenience chains urging them not to make such a move. The non-governmental organisation Greeners Action yesterday said it was deeply concerned about reports that the Circle K and 7-Eleven chains were considering using paper bags - a move they said would undermine the levy's effectiveness in curbing bag abuses. 'We feel very angry and disappointed. If they insist on pressing ahead with their plans, we would not rule out escalating our action and ask the public and other organisations to boycott such reckless businesses,' said Angus Ho Hon-wai, head of the group. The Circle K chain last week said it was planning to give paper bags to customers who refused either to pay the levy or to leave a refundable deposit to borrow environmentally friendly shopping bags. 'This is not intended as a means to avoid the 50 cents levy - which is not payable by the retailer anyway - but to provide a convenient solution and a transitional measure while we attempt to change consumers' shopping habits,' a spokesman said. 7-Eleven was reportedly considering a similar measure last week, but it could not be confirmed. Mr Ho said Greeners Action had noted a recent trend of supermarket products being prepackaged in plastic bags, to avoid the bag levy. The government should plug the loophole by regulating over-packaging, he said. Caroline Mak Sui-king, chairwoman of the Hong Kong Retail Management Association, said individual retailers might have their own considerations, strategies and responses to the levy, and it was difficult to comment on specific cases. 'While I believe most retailers will make arrangements to facilitate the levy, the groups and public should also understand the pressure facing the retailers amid current economic situations,' she said. People should not be 'oversensitive' to prepackaged products like rolls of tissues, which have been in use for a long time, she said.