The constant drive to reduce the operating expenditures is having an adverse effect on the health and safety of the public

John Moist, GMB organiser

But the GMB union has claimed that current staffing levels are not adequate for the winter months.

It has concerns that a third of the company's engineering contractors were working more than 48 hours a week.

GMB organiser John Moist said the situation gave the union "considerable cause for concern".

"The constant drive to reduce the operating expenditures is having an adverse effect on the health and safety of the public through the constant reduction of the number of people available to respond to leaks," he said.

Shift system

"The response time is moving out, the standards of service are not being met and these things have to be addressed by Transco as a matter of urgency."

The company admitted that some staff had worked more than 48 hours to deal with peaks in emergency work.

But it said discussions were under way with the unions on a shift system and the retraining of contract workers to address the issue.

And Transco stressed that full resources were available to enable it to respond competently to all gas escapes all year round.

The houses in Dundee had to be demolished

The company has been under scrutiny after an explosion killed two people in Dundee last month.

The procurator fiscal in Hamilton is also considering a Health and Safety Executive report in to last year's blast in Larkhall, which claimed the lives of the Findlay family.

It is believed that the question of whether Transco should face prosecution for alleged breaches of health and safety laws and pipeline regulations is under consideration

Meanwhile, there have been calls for the crime of "corporate killing" to be introduced into Scots law to make firms more accountable for fatal accidents.

Labour MSP Cathy Jamieson claimed that the existing law was ineffective in such cases.

However, the Scottish Executive said there were no plans to consider such a move in Scotland because an equivalent charge could be brought under common law.