The Co-operative Group is bidding to change consumers' perceptions of its stores by revamping its premium range Truly Irresistible and more than doubling the number of lines.

As many as 67 new products have been launched, including pizzas, quiches, pies, meat, cheese, fresh produce, marmalade and biscuits, in a move that takes the number of products in the range to 120.

The society is hoping the initiative will persuade consumers that shopping in Co-op stores isn't just about convenience purchases.

The colour of the packaging has been switched from mauve to black and the Food Standards Agency's traffic-light scheme is front-of-pack.

To mark the launch, a number of items in the range will be reduced in price by 20% this month.

"We are working hard to show customers that the Co-op is good with food," said Kate Jones, head of range development for food retail. "People can come and do their full shop with us."

More premium lines are planned for the summer, including baby beetroot in a sweet chilli marinade, cheese stuffed red peppadew, topped ciabatta and dipping oils, to bring the range up to more than 200.

The society will also roll out Summer Eating ranges including BBQ vegetable kebab kits, sweetcorn kebabs with chilli and lemon oil drizzle, Chinese chicken drumsticks, and BBQ and tableware lines.