THE Conservative opposition group on Darlington Borough Council is demanding to know why more steps were not taken to research the location of a gas pipe before the Pedestrian Heart project got under way.

On Wednesday, The Northern Echo revealed that the controversial £6.5m pedestrianisation was likely to be delayed by months and could cost up to £780,000 more than planned - because of a 100-year-old gas main.

The pipe, which serves the west of Darlington, was not buried as deeply as the research had indicated.

Last month, a mechanical digger working near the Joseph Pease statue struck the pipe, causing a gas leak.

Councillor Jim Ruck, the Conservative group spokes-man on the environment scrutiny committee, said: "This could have been very serious for Darlington. This town is very lucky that the gas did not hit a source of ignition."

The group believes the Labour-controlled council should investigate who was to blame for the mistake - and seek compensation for the extra expense.

Coun Ruck said: "Who is going to pick up the £780,000 tab on this. I have a feeling it will drop on the taxpayer."

Yesterday, a council spokeswoman said: "There isn't anyone we can blame for this and we feel we did everything reasonable before starting work to determine the exact location of all the underground utilities."

Coun Ruck disagrees - the council has said radar surveys, which were carried out to determine the location of the pipe, were not 100 per cent accurate.

He said: "It seems to me to be critical to know where the cast iron main is. Cast iron of this age of very brittle."

The council spokeswoman said: "The location of the pipe given to us by the utilities companies was confirmed by the radar survey.

"We could have carried out work to make a series of trial holes in the highway to see what was underground. However, this would have been expensive and disruptive."

But Coun Ruck believes spot excavations should have been carried out. He said traders in the town centre were suffering because of the building work and called for businesses to be compensated.

The council spokeswoman said there were no plans to compensate businesses.

"They have the opportunity to apply for business rate relief while work is carried out, and many of them already have done this.

"The evidence we have, in respect of transport figures, does not show any significant decline in the number of people coming into Darlington town," she said.