By Emma Wilkinson
Health Reporter, BBC News
Smoking bans are routinely flouted in many NHS hospitals, researchers say.
Most hospitals do not allow smoking in the grounds
Researchers spoke to three-quarters of hospital trusts in England last year, with two-thirds reporting non-smoking rules were being broken daily.
And spot checks by a team at Nottingham University uncovered staff and patients lighting up even though hospitals should have been smoke free since 2006.
The government said it did not accept the findings and had no evidence to show regulations were being broken.
National guidance published in 2005 stated that smoke-free policies should cover hospital buildings and grounds because of the role of hospitals as "health promoting" organisations.
There have been exemptions for mental health trusts but these are due to come to an end in July.
The study took place in 2007 before the ban on smoking in enclosed public places started in July but after the NHS smoke free policy covering buildings and grounds took effect.
The researchers questioned three-quarters of acute health trusts in England and carried out checks in 15 of them.
More than eight-in-10 hospitals and six-in-10 mental health trusts had implemented non-smoking rules in both premises and grounds by February 2007, results published in journal BMC Health Services Research show.
About half of hospitals allowed some exemptions, mainly for bereaved relatives or psychiatric patients, in outdoor areas or smoking rooms.
But when it comes to enforcing the rules, hospitals seem to struggle, the research suggested.
Two-thirds of acute trusts and over a third of mental health trusts said the rules on smoking were being broken on a daily basis.
When researchers visited hospitals they saw patients and visitors smoking at 94% of them and staff smoking at 35%.
Hospitals told the researchers they were also battling with litter from cigarette butts and crowds of smokers congregating outside hospital entrances.
The researchers said the flouting of non-smoking rules appeared to be "widely tolerated" in hospitals.
And they warned now the smoking ban had come into force, the NHS could fall behind other work and public places.
Professor Ann McNeill, an expert in health policy and promotion at the University of Nottingham, said: "It tends to undermine efforts to use the hospital to encourage people to stop smoking.
"But it's not an easy thing to do. We want to acknowledge that trusts have made a lot of progress.
"We want to get the message across on how dangerous smoking is and it should not be tolerated but there needs to be support."
She added that one problem was a lack of clarity on who was responsible for enforcing the rules and questioned whether it should fall to medical staff or security guards.
Co-researcher Elena Ratschen added that trusts had all been very keen on smoke-free policy.
"It would be helpful to have further guidance on how to support staff with enforcing the policy."
She added: "It's no use just putting up signs, you have to provide support for people to quit and that needs funding."
A spokesperson for NHS Employers said NHS trusts were taking a similar approach to any other organisation in ensuring the smoking ban is enforced.
"In addition to complying with the legislation and making staff and patients aware of the legal requirements, employers have been encouraged to offer staff training to help them understand the new law and their responsibilities and to provide both staff and patients with support to quit smoking."