A glorious grand white elephant?

The business consortium that wins the bid this December to build the high-speed continental rail link between Kent and London will also be the lucky winner of an officially "derelict", Grade I-listed, 250-bedroom, Gothic Revival hotel designed by Sir George Gilbert Scott and completed in 1876. Well, perhaps not quite so lucky; the former Midland Grand Hotel (known, since it became railway offices in 1935, as St Pancras Chambers) will be one of the least wanted of all Christmas gifts this year.

St Pancras Chambers might be one of the greatest buildings of the 19th century, yet it is in grave danger of becoming little more than a liability. It could even go the same, sad way as Battersea Power Station - cooed over, gawped at, but changing hands from one careless owner to the next until demolition beckons.

None of the private sector railway companies wants to own this neo-Gothic masterpiece, because they can see no profitable future for the grande dame of Victorian railway architecture. This seems particularly sad, given that British Rail has recently spent five years and pounds 10m renovating the exterior of the Gormenghast-like building in a brave attempt to make it secure, weatherproof and an unforgettable ornament on the capital skyline.

To spend pounds 10m and then let the building fall into unwilling hands seems a silly thing to have done. Yes, the pinnacled outline, vertiginous spires and curving front of salmon pink bricks are both eye-catching and breathtaking, but what is the point of maintaining at great expense a building with as little purpose as a redundant superstore (coming your way soon)?

Yet, something must happen. It has taken so much time, money, emotional and physical energy to save St Pancras Chambers for future generations, that it must not be allowed to fall into a disrepair again or, accidentally, to catch fire. St Pancras Chambers must not be allowed to go the way of the Euston Arch, destroyed on the whim of Harold Macmillan in 1962, a piece of family silver not so much sold off as melted down, and for no good reason.

It was the gratuitous demolition of the Euston Arch that led to a vigorous campaign by the late Sir John Betjeman to get St Pancras saved for posterity. The campaign worked, but only up to a point. For although weasel words were spoken about the need to preserve Scott's masterpiece, the building remained all but abandoned. The more the roof leaked, the deeper down in the serpentine bowels of the building sank the offices of British Rail's London Midland Region.

Meanwhile, down in the cellars (designed to store barrels of Burton's ales) heaps of combustible materials were stored indiscriminately. In 1979, the building was declared unsafe by fire officers and abandoned. Prostitutes, drug peddlars and down-and-outs moved into the crypt-like cellars, while pigeons occupied upper storeys, covering floors and stairs in heaps of 100 per cent impure London birdshit.

In 1985, plans were drawn up for the revival of St Pancras Chambers as a hotel. Speyhawk, a firm of developers, and YRM, architects, teamed up to produce designs that made great sense and which would have maintained the great character of the building. These were scuppered by three broadsides - the collapse of the London property market in 1989 and of the London Regeneration Consortium, which was to have redeveloped the railway badlands to the north of King's Cross-St Pancras; uncertainty over the routing of the high-speed Channel Tunnel link; and the unfathomably squalid character of the surrounding area. Traffic noise, sirens, alarms, car fumes, brake dust and other forms of pollution swamp the building in a miasma of urban fug.

Fate intervened on the side of St Pancras Chambers in 1990; the Clapham railway disaster of that year spurred Bob Reid, then chairman of British Rail, to instigate a thorough tightening of railway safety. This review included railway-owned buildings, such as St Pancras Chambers. At the time, the Victorian building was behaving like the skin-shedding serpent it resembles, threatening passers-by with shards of finials, segments of chimneys and spears of iron from wavering balustrades.

British Rail appointed the Conservation Practice to make the building safe and secure. In doing so, the architects have gone beyond the call of duty, working prodigiously to map, make good, preserve and enhance the glory that was Gilbert Scott's (and the directors of the Midland Railway).

"When we moved in five years ago," says Barry Shaw of the Conservation Practice, "the only drawings of the building available to us were Scott's original competition drawings of 1865. Since then, we've recorded every last detail - a store of knowledge invaluable to anyone willing to take on the building in future. Our remit came to an end on 17 March this year but it would be sad if our research was wasted."

Shaw's colleague, Daniel Shabetai, has virtually lived in St Pancras Chambers since restoration work began in 1990. "We've colonised a small part of the building, but very little of it has electricity, drains or running water. It is a watertight shell at the moment, but it could be a magnificent multi-purpose building incorporating shops, bars, restaurants, conference rooms and loft living space in the upper storeys and attics. We've produced several feasibility studies to show how the building could be occupied by a number of enterprises over time. English Heritage is happy to see St Pancras Chambers used in this complex way, because we are sure it can be done without damaging or reducing in any way the stature and design of the building, and because St Pancras must have a profitable purpose if it is to survive."

Several international hoteliers have looked at St Pancras Chambers during the past five years, but the cost of turning it into a five-star hotel (between pounds 100m and pounds 180m) have been a stumbling block. While St Pancras Chambers needs a business champion (preferably someone with a passion for Gothic Revival and pre-Raphaelite design), it also needs a boost from the public sector. The reason is simple. St Pancras can never be home to excellent bars, restaurants and Manhattan-style lofts until its setting is raised from one of promiscuous squalor into one of civic grace. That requires a co-ordinated policy by local authorities and developers. At the moment, pimps ply their less than divine trade in the very shadows of the spires and pinnacles of St Pancras.

This might well change if and when St Pancras station becomes the terminus of the new high-speed Channel link. There are, however, many who believe the continental trains will get no closer to St Pancras than Stratford, several miles to the east. In that case, the future of one of the most exuberant, most thoroughly uncompromised and best loved buildings of Britain will again, like its namesake, be under threat of martyrdom.

We need to stop this rot now. But, how do we begin when the railways, London's government and every other relevant body has been split and split again into tiny fiefdoms with no eye for the big picture, and certainly not for one as colourful, idiosyncratic and magnificent as the former Midland Grand Hotel?