By Jane Dreaper BBC News, health correspondent

The NHS has long relied on volunteers to help out at those visiting hospitals.

Providing tea and a sympathetic ear is one of an NHS volunteer's roles

Now, a commission is starting to take evidence about how people can be encouraged to volunteer, and how to make sure that those who put themselves forward don't end up delivering services on the cheap.

And a guide has been produced to make sure that the army of volunteers within the NHS is better managed.

William Walsh is an NHS volunteer. For 81, he cuts a sprightly figure.

He helps patients find their way through the maze of different departments at the busy Royal Free Hospital in north London.

This "meet and greet" role is one of dozens that volunteers undertake in hospitals. They might help in the chapel, or assist patients by helping feed them or running errands.

Other volunteers are returning from ward rounds with the shop trolley where they've been doing a roaring trade in boxes of chocolates.

'Spirit-building'

Diane Goldman manages the Royal Free's 500 volunteers.

It's not unusual for a big hospital to have this level of unpaid help, and Diane admits she has to be firm sometimes.

Volunteers have in a sense had to earn their spurs Christopher Spence, Volunteering England

"I had a volunteer being asked would they go and feed someone's cat. No they can't do that - they can't do anything outside the hospital grounds.

"I get people who are over-involved emotionally. Sometimes they get rather upset, because obviously some patients come in for a new knee - others are very sick and may die."

One of Diane Goldman's star volunteers is a former refugee from Uganda, Justine Tusabe, who's popped in with her son.

Christian is seven years old, and severely disabled.

Justine began volunteering to thank the Royal Free for the help staff have given Christian. She contributes about 15 hours a week and has found the work rewarding.

"Taking care of Christian on my own becomes so lonely," she said.

"Coming in here and helping others in the hospital, who are in worse situations, helps build my spirits up, which in turn helps Christian."

'Earning their spurs'

Justine helps patients with their shopping and also works with children on the maternity ward and in the playroom.

Her efforts have been recognised with an award, and she'd like to eventually work in the NHS as a healthcare assistant.

This is an example of how volunteering can work well. But the commission looking into its future has already had responses about some of the negative aspects.

One response on its website said: "Many ordinary volunteers, rightly or wrongly, often have very low status, and I firmly believe that on balance this status is decreasing. I feel we are often patronised like schoolchildren."

Another complained: "Poor working conditions are a reality, as is using volunteers as cheap labour."

The Department of Health is looking very hard at the way services are commissioned with and by the voluntary sector Anne Viney, Cruse

The government says often there's inconsistency in the way volunteers are managed, particularly in the NHS.

Christopher Spence runs Volunteering England, which has produced a guide to encourage better practice.

He says that although the tradition of volunteering in the NHS goes back a long way, there's no centrally collected data.

"Volunteers have in a sense had to earn their spurs," he said.

"They do come up against attitudes among paid staff that somehow volunteering is a threat to their professional job, or that there isn't a contribution for volunteers to make.

"They can add enormous value, and make the patient experience more human.

"But they want to be well managed - and there need to be building blocks in place, so each volunteers knows what training they'll get, what expenses they can claim and what duties they can expect to undertake."

Finding a balance

As well as the thousands of helpers actually based in hospitals, charity volunteers often feel they prop up the NHS.

The bereavement charity Cruse is trying to balance the goodwill generated by its substantial volunteer base with the need to be businesslike in today's contract-driven NHS.

Anne Viney says that while volunteers don't want to sit around filling in forms, it's important to join up with more official sources of funding and training:

She said: "The Department of Health is looking very hard at the way services are commissioned with and by the voluntary sector.

"We're looking for joint working - we're looking for reasonable contracts, and for the skills of our volunteers to be properly used."

Cruse's helpline receives about 6,500 calls a month - though they manage to answer only about a quarter of them.

Two-thirds of those who contact Cruse, because they're distressed about a death, do so because it's been suggested by their doctor.

The chief executive, Anne Viney, said: "We have one staff member for every 44 volunteers, and although we'd like to be better resourced, we would never want to change the volunteering drive behind our organisation."

The Commission on the Future of Volunteering is trying to find the best way forward for the millions of people who offer their unpaid help.

The key, they say, is getting politicians to support volunteering without stifling the enthusiasm of those who take part.