Patients given help to stop smoking can more than double their chances of quitting compared to a smoker given no help, a study found.

Oxford researchers showed that if a patient in hospital has intensive counselling and follow-up sessions for at least a month, they are twice as likely to quit compared with a smoker receiving no help.

The study, published in the journal Thorax, looked at 5,738 smokers in Europe and North America, between 1990 and 2000.

The UK's two largest cancer charities said the research showed more help must be given to smokers wanting to quit.

Dr Marcus Munafo, of Imperial Cancer Research Fund's General Practice Research Group, said: "The results from the study show that giving help to patients while in hospital will double the chances of success.

"Smoking is the biggest single cause of lung cancer. By stopping, you can significantly lower your chances of developing the disease."

He said few medical professionals give advice or support to people wanting to quit while in hospital.

Dr Lesley Walker, director of cancer information at the Cancer Research Campaign, said: "This study has shown that with the right support, the quit rate for patients is doubled."