Membership of the Co-operative Group's dividend scheme has swelled by 500,000 since it was relaunched a year ago.

The profit-sharing scheme was relaunched in September last year, allowing members to use their dividend cards across all the society's businesses.

It now has more than 2.5 million active trading members. This number is set to increase further when more than one million members of United Co-op, which merged with the Co-op Group in July, join the scheme later this year, as well as 220,000 members of Midcounties Co-op, which last month announced plans to adopt the card.

"The growth in members demonstrates that many consumers share our belief in self-help, social responsibility and democracy," said Co-op Group director of brand Jemima Tomlinson.