Ms Wyner, 50, who grew up in Barnes, was jailed for five years in December after being found guilty of allowing heroin to be traded on the premises of the Wintercomfort day centre.

The former St Paul's School pupil took over as director of Wintercomfort in 1995. Last week she spoke to the Comet from Highpoint Prison, Newmarket, to express her concerns about the implications of the case on other homeless projects.

She said: "I've worked for 20 years with the homeless and the dispossessed, trying to put together shattered lives.

"It is not easy work and I fear that my prosecution will not encourage others to try it. I also fear that other homelessness projects will be discouraged from working with drug addicts.

"Prison is very hard, the separation from my family especially difficult. I have not been apart from my husband for 20 years and my youngest child is in the middle of her GCSEs. I feel very sad that I can not be there to help her through.

"I think it is fantastic that the Surrey Comet is taking the case up and I am very grateful. I am sure that pressure from the public does make a significant difference in these cases."

The mother of the jailed director, Anna Wyner, said she has gained strength from the enormous public support generated in the wake of the trial.

She said: "I was shocked when Ruth was arrested but we thought she would get a suspended sentence. Then the judge gave her five years.

"The law now needs to be changed. The danger is that if it is not changed, people will not come forward to work with the homeless. They will be nervous about the risks involved."

With the news this week that Ruth and her colleague John Brock have been granted leave to appeal against their conviction, Mrs Wyner said she remained optimistic.

She said: "It is very good news.

Ruth will be pleased to know that there is now a date set. The awful bit is waiting for the day."