THE campaign to prevent carbon monoxide deaths has taken a new turn with a warning to keep climbing plants away from air vents and flues.

Garden centres throughout the country are to back the move with posters and on-the- spot advice.

British Gas experts, who are aiming to drastically cut down the 30 deaths a year from the so-called silent killer, posed the question: "Could your clematis be killing you?''

The company has written to hundreds of garden centres and sent out safety posters.

It wants retailers to remind customers of the dangers of letting climbing plants block up air vents and flues leaving them at risk from the deadly poison.

A British Gas campaigner had spotted the publication of a photograph in a gardening magazine, which showed a prized clematis growing through a duct next to a water boiler.

A spokesman said: "Though the plant may have looked pretty, it actually posed a serious risk of blocking the vent and causing problems with the boiler which could lead to lethal carbon monoxide fumes being produced."

British Gas sent out a warning letter, which has won the support from the Garden Centre Association (GCA).

Chris Beilby, head of safety at British Gas, said yesterday: "People often plant attractive climbers and shrubs to hide a less appealing aspect of their house.

"But climbers in particular can be very fast growers and people may not be aware of just how invasive it has become. And if a vent is affected, then it could be deadly.''

Steve Myatt, chairman of the GCA said: "Avid gardeners may be keen to hide features such as pipes and vents with plants, but it is vital that they are made aware that certain vents must be kept clear."

The Northern Echo launched its Silent Killer campaign following the death of Anne Brennan, 19, from Houghton-le-Spring, Wearside, who died ten years ago while in student accommodation in Durham City.

It called for a huge advertising campaign to be funded by a compulsory levy on gas suppliers - a proposal made by health and safety chiefs as far back as 2001.

No legislation was brought forward by the Government in the last parliament, which meant such a campaign could only take place if the suppliers agreed to pay for it voluntarily. Since then, the Energy Retail Association, the trade body for gas suppliers, has improved warnings on leaflets and websites, although it rejected expensive TV adverts.

Read more about the Silent Killer campaign here.