The damage done to the Channel Tunnel fire is so bad that is likely to be at least six months before it fully re-opens, and could take far longer.

That is the bleak assessment of fire chiefs, who have told councillors they regard the blaze as far worse than the one in 1996.

Kent chief fire officer Bill Feeley briefed members of the Kent and Medway Fire Authority at a meeting during which councillors from KCC and Medway council were shown graphic photographs of the damage taken by firefighters at the scene.

The briefing was held behind closed doors - but sources have told the Kent Messenger Group they were informed the fire was more severe than has yet been publicly acknowledged, as is the damage.

Listen: Eurotunnel's Charlotte Brookes gives an overview of services >>>

The photographs distributed at the meeting reveal the fire's intensity was such that, in some parts, it completely stripped away the tunnel lining back to the supporting steel structures.

Sources say the meeting was left in little doubt that the fire was by far the most serious to have happened in the tunnel.

"It was described as worse than 1996 and would possibly take longer to repair and re-open," said one member, who asked not to be named.

Meanwhile, Eurostar trains should be back on track by the end of the week.

The first of three 10-and-a-half mile sections in the north tunnel reopened Monday, with a second on Wednesday.

But it could be some time before the final 10-mile stretch of track reopens.

Cllr Bryan Cope (Con), the chairman of the fire authority, refused to comment on what was said at the meeting, saying it would be inappropriate to do so before the outcome of any official investigation.

However, he registered concerns there had now been three incidents in 12 years when the original risk assessment, made at the time the tunnel opened, suggested there would be one every thousand years.

"That will need to be looked at," he said. "Obviously, it was a serious fire and when it re-opens depends on how quickly the work can be done."

Meanwhile, KCC warned any prolonged closure of the tunnel risked gridlock in the county.

Cllr Keith Ferrin (Con), cabinet member for highways, said: "In the normal run of things, we usually see cross-Channel traffic increase between now and Christmas by 20 per cent.

"If we get spells of bad weather affecting the ferries, whatever existing problems we have will get worse. We will have to cope with the traffic implications and that worries me."

In a statement to us, Kent Fire and Rescue Service (KFRS) said: "KFRS can confirm that the operational response to last week's Channel Tunnel fire was discussed during the open part of the meeting. KFRS is extremely proud of the way operational and support staff dealt with the incident and key points of that response were shared with authority members.

"Under the exempt part of the meeting, contractual issues relating to the Channel Tunnel were discussed. As a result of its exempt status, the authority deems it inappropriate to comment any further on this issue."