A Norfolk MP has welcomed a positive step forward in a couple's eight-year battle with a farmer over the impact that gassing - or fogging - of stored potatoes in a neighbouring barn has on their lives.

A Norfolk MP has welcomed a positive step forward in a couple's eight-year battle with a farmer over the impact that gassing - or fogging - of stored potatoes in a neighbouring barn has on their lives.

Grandfather Ritchie Warnes, 62, and his wife Sandra, 59, of Somerton Road, Martham, near Yarmouth, claim they are forced indoors by a “chemical fog” each time potatoes are treated to stop them sprouting at the store on Church Farm.

Mr Warnes, a self-employed block paver, said he had been left with an inflamed throat on one occasion and his wife blames her persistent cough on exposure to the chemical, Chlorpropham.

He said the problem had begun when the barn was converted to a potato store in 2001 and persisted throughout the storage season from November to May when they often had to keep their grandchildren indoors.

Mr Warnes has previously commissioned two toxicology reports, including one by a Leeds University professor, which confirmed the potential health hazards of Chlorpropham, a known skin and eye irritant.

He is also pressing for the barn's planning permission to be re-examined because he claims it has become a store predominantly for potatoes grown away from the farm.

Having previously investigated and declined to take action, the Health and Safety Executive (HSE) is now looking into the case again following the intervention of the Parliamentary Health Service Ombudsman at the request of local MP Tony Wright.

While declining to personally take up the case, the ombudsman suggested in a letter that the HSE could go further in their investigation.

As a result, HSE inspectors have agreed to be at the farm with a toxicologist to witness the next time the potatoes are treated. They have also requested Mr Warnes' medical records to examine his health claims.

Welcoming the fresh investigation, Mr Wright said: “It is unacceptable for the Warnes to be put in the position they are in.

“No one wants to restrict farmers from doing their job but they have a duty to be responsible in the way they put down insecticides.”

Farmer Henry Alston insisted fogging only took place, on average, three times during the period early November to May.

He said they had nothing to hide as they did everything 100pc legally and would be totally open with the HSE inspectors.

Their methods of crop production had to be approved by the Assured Produce Scheme, he added.