FIRE chiefs will be taking the unusual step of appearing at a public inquiry next year - to oppose the A303 tunnel planned for Stonehenge.

Wiltshire Fire Brigade will tell a government inspector that the tunnel - actually twin tunnels, one for each direction - intended to improve safety and the environment around the world heritage site would pose a grave threat to public safety.

The tunnel plan has been devised to conceal traffic from the view of Stonehenge visitors after the A303 past the ancient monument is turned into a dual carriageway.

But fire chiefs are concerned at what they see as a deficiency in the plan's fire precautions and have warned the tunnel could be a tragedy waiting to happen.

Their formal objection has already been lodged with the inquiry office. They complain that the Stonehenge tunnel would not be radically different from other tunnels around the world where hundreds have died in fires during post-war years.

Safety in the constructions has depended on smoke ventilation without fire suppression systems to accompany it.

Wiltshire's assistant chief fire officer, Eugene Johnson, told the Journal: "A fire suppression system is necessary.

"We believe a solution based on smoke ventilation is not the only way and not the best way.

"We would like to see smoke ventilation and fire suppression."

Suppression can comprise a sprinkler system or a mist system, which produces a fine spray that is often more effective in restricting or containing fires.

Mr Johnson believes that the design proposals make unrealistic assumptions about the size of fire that might occur.

"Our concern is that something will happen in the tunnel outside the design fire size, the fire will be worse than people expect and this will cause injury or death."

He said that the usual pattern of a tunnel fire was that it developed extremely quickly and people had no time to escape.

Mr Johnson favours suppression measures, particularly because they stop the flames from spreading in the immediate area.

But he fears that the case for suppression methods is weakened because ventilation engineers dominate tunnel design.

Mr Johnson said fire safety was vitally important on a road as busy as the A303, particularly with a predicted increase in the number of petrol tankers using the route.

He has also warned English Heritage that a serious fire would probably close the tunnel for months, meaning the diversion of traffic on to other roads and through surrounding villages - causing more problems.

His other big worry is that, if obvious fire precautions are not taken, the brigade could put its firefighters at unnecessary risk.

Mr Johnson estimates that fire-suppression installations would increase the bill for the tunnel by no more than £3m.

Highways Agency project director Chris Jones told the Journal that the agency is currently in discussions with Wiltshire Fire Brigade on the points they have raised.

He said: "We are looking to resolve them in due course."

Inspector sets out programme for tunnel inquiry: Page 13