A burst water main has caused so much damage to a city centre street that buses are in danger of toppling over.

In January, Glasgow road bosses noticed a problem on Renfield Street which is used by 230 buses an hour.

They found that a leaking water main had weakened the surface of the route which was buckling under the weight of traffic.

Glasgow City Council head of roads Andy Waddell said: “We had to close off that section of road because double-decker buses were in danger of tipping over.

“About six weeks ago Scottish Water finally confessed it was their problem and said they would be repairing it but to date no work has been done.”

Robert Booth, executive director of land services, added: “Scottish Water has agreed it is their responsibility, but all they have done is dig a hole and walk away.

“There was water on the surface of the road and when they drained off their various mains, the road dried out.

“We cannot fix the problem because we are not allowed to, so it must be very frustrating for the public.

“We are in almost daily contact with Scottish Water trying to find out when they are going to start work. They say resources are tight and their priorities are elsewhere but this is a major bus route, and the situation is intolerable.”

Scottish Water denies the problem is caused by a burst main. A spokesman said: “We have attended Renfield Street near its junction with West George Street on a number of occasions since damage to the road was reported in April.

“We have excavated and carried out investigations at this location and in nearby Renfield Lane. We also shut down a section of pipe as part of this investigative work.

“We have found no evidence of a burst water main. Some further investigative work in the area is planned for next week with a view to establishing if there is a burst main and, if so, whether the water rising and road damage is linked to that.”

However, Mr Booth said: “As far as we are concerned, this is a Scottish Water problem.”

He and his team are frustrated by the Renfield Street problem as they are in the middle of a £12 million blitz on potholes following the worst winter for 40 years.

Between October 2007 and March 2008, a total of 3501 potholes were reported in the city but between October last year and this month the number soared to 10,200.

In a bid to tackle the problem, the council has agreed to spend an extra £8m this year on repairs, bring the total budget to £12m.

However, it is estimated it will cost £71m to put right years of damage.

The money spent this year will allow 90 junctions and 300 roads to be resurfaced, up to one-fifth of city centre roads resurfaced and 150 sunken manholes repaired.

Since April, about 600 potholes have been permanently repaired and 84 large stretches of road resurfaced.

Mr Booth says it is beginning to have an impact as the number of pothole reports have dropped from 902 in the last week of February to 321 in the week starting June 20.

Work will step up a gear next month when two teams of private contractors will begin a £2m contract aimed at helping council staff with the pothole repairs.

Christine Francis, the council’s roads maintenance boss, said: “There will be an additional six squads working on the street in August.”

The council has identified 276 city streets which require repairs covering 1000 sq m.

Of those, 110 have been completed and the balance should be finished by the end of October. It is also planned to resurface 170 streets in residential areas to prevent them deteriorating.

Almost half the work has been finished, with the balance due to be complete by September.

A total of 106 schemes were planned on major roads which have more widespread structural failure, and 32 have so far been completed.

Despite this, TV celebrity chef and motoring campaigner James Martin yesterday described Glasgow’s roads as the “worst in Britain”.

On a mission to find the best and worst road in the UK, he added: “If they don’t fix the roads correctly, then it’s us who will be paying for their mistakes.”

Glasgow City Council estimates it has dug up approximately 40,000 tons of material while carrying out the work.

In the past, this would have been dumped into a landfill site but is being recycled.

Mr Booth said: “We would previously have had to pay £48 for every ton we dumped, but instead we not only save that money but get a payment from the recycling company.”