Such businesses with a social mission have to restrict their membership and appoint audit committees with independent members, among the ways to make them more accountable to their members.

These changes to the Co-operative Societies Act are prompted by the growth in co-ops and the more competitive business environment, said Minister of State (Community Development, Youth and Sports) Yu-Foo Yee Shoon.

No longer are they merely the community self-help organisations of the past where members knew each other and depended on mutual trust and peer pressure to safeguard their interests, she noted.

The 87 registered co-ops now have a reach of 1.7 million members, including big ones like NTUC FairPrice and NTUC Income.

Of particular concern are the 41 co-ops that take in deposits from members and give out loans. Their members are mostly from the working class who cannot afford to lose their savings, averaging about $5,000 per person.

Hence, these credit co-ops which manage total deposits worth $1 billion are the key target of the changes.

For example, the new rules spell out the duties and accountability of board members of all co-ops, and require co-ops to comply with accounting standards.

These co-ops cannot accept new members from the general public. Deposits and loans will be similarly restricted to, say, members and immediate families.

However, all co-ops will get more flexibility in other areas.

For instance, they will no longer need the Registrar's approval to invest in property and other co-ops, or to set limits on how much honoraria can be paid to members of the management committee.

Various parties such as the Singapore National Co-operative Federation and the National Trades Union Congress were consulted on these changes, said Mrs Yu-Foo.