Primary care trusts could link up with foundations by sharing public membership bodies that drive local health priorities. PCTs are considering recruiting public members to counter perceptions they are undemocratic and overly centralised.

Allowing the public to be members of both foundations and PCTs is one possible route to better patient involvement - meeting the target of "robust" public involvement under world class commissioning.

Other approaches being considered include large public consultations and citizens' juries. PCTs' models will be assessed under world class commissioning later this financial year.

Hull PCT - believed to be the first to have proposed joint membership with neighbouring foundations - intends to link up with Humber Mental Health Teaching trust and Hull and East Yorkshire Hospitals trust, both of which are applying for foundation status.

The PCT aims to recruit 1 per cent of the local population - 2,500 people - for joint membership in the first year of the scheme.

It would have three tiers of members, including a tier that canvasses the views of the wider population and a top scrutiny tier. Patients, staff, the voluntary sector and hard-to-reach groups will all be targeted for membership.

Staff hope the members can drive health service reform locally.

PCT chief executive Chris Long said: "For us it's about providing a continuous feedback loop. If you actually share a common membership with foundation trusts, that does give a more 'whole systems' approach if you're changing things." Walsall teaching PCT has also drawn up a joint membership scheme.

Richard Lewis, director of Ernst & Young's health advisory practice and co-author of a King's Fund report on patient involvement, said it was right that world class commissioning was putting a focus on a more intelligent view of what populations wanted.

But he warned that PCTs would need to manage members' expectations about the influence they would have, and ensure that members understood what PCTs did.

He said: "It's reasonable that trusts establish a set of mechanisms to get people to help make decisions where PCTs have local discretion. But there are elements of what is still a national health service that are not up for negotiation."

See the Good Management section for more on patient involvement.