Concerned pensioners have warned that metal thieves could trigger an explosion by tearing newly fitted copper pipes off the outer walls of their homes.

They accused the National Grid of putting the safety of residents in their cul-de-sac at risk after replacing old underground pipes with exposed metal pipes as part of routine maintenance work.

National Grid bosses insisted the job in Chadwell Heath was approved by the Health and Safety Executive and urged residents to call the national gas emergency helpline if they detected a leak.

But Chadwell Heath landlord Bernard Sales, 76, said: “It appears gas meter fitters and the gas board are allowed to put my tenants at risk of gas explosion and gas loss at their expense by exposing some 19ft of copper pipe to public vandalism.”

Pensioner Beryl Selvage, 88, added: “It’s a danger. Not only that, they have defaced the properties.”

A National Grid spokesman said: “This work forms part of our essential gas mains replacement programme agreed with the Health and Safety Executive.

“We consulted with the affected residents in the maisonettes about installing the new pipes and meter boxes before carrying out the work.

“We are talking to a number of residents who have expressed concerns about the work and will look into whether there is anything we can do to alleviate their concerns.” The gas emergency line can be reached on 0800 111 999.