The campaign to stop the march of huge pylons across the Cheddar Valley hotted up this week.

Distinctive yellow posters from the No Moor Pylons group appeared all over the area and leaflets urging people to support the campaign are being delivered house to house.

One of the campaigners, Fiona Torrens-Spence of Stone Allerton, said: "We aim to raise local awareness of the threats posed by National Grid's proposed pylon routes and draw attention to alternative routes.

"We are immensely encouraged and buoyed up by the amount of support we are receiving especially from people who normally steer clear of group action or who are frail and elderly."

Cheddar Valley MP David Heathcoat-Amory told a packed meeting in Wedmore on Sunday that he was confident he could stop pylons marching through Mark, Blackford and the Allertons – but couldn't give the same assurance for another route.

He was answering questions at the meeting, which had been organised by the No Moor Pylons campaign and attracted an audience of 173 worried local people.

Mr Heathcoat-Amory said: "I believe I can stop corridor two but I can't do it alone, it has to be you as well. It's most important that your campaign keeps up its momentum.

"It would be wrong to save one set of residents at the cost of others. There's just as much objection to corridor one on environmental grounds.

"There's an existing power line up corridor one and a lot of people are affected because it runs up part of Mark village. I can't give you the same assurance about corridor one as it already has pylons on it."

The corridors he referred to involve National Grid putting up taller, more powerful pylons to carry extra electricity from a proposed nuclear plant at Hinkley Point C.

Corridor one is the existing route through Mark. Corridor two is a new route over the Somerset Levels.

He said he was keen to pursue putting cables underwater from Hinkley Point to Seabank in Avonmouth. He acknowledged the complexity in transforming AC into DC and back again but believed it could be done and thought National Grid's £1 billion price mark on "the marine option" was an estimate.

He said after corridor consultation ended then the Infrastructure Planning Commission (IPC) would give approval or not.

Andrew Scott of No Moor Pylons opened the meeting with: "We feel we have been put between a rock and a hard place and neither corridor is acceptable and that's the course of action we have taken with this campaign."

The campaign's phase one is responding to National Grid using their process. Phase two is a petition telling the firm to go back to the drawing board and reconsiders their options.

When asked how many people did not get letters from National Grid inviting them to a consultation, about a third of the room put up their hands – roughly 58 people.

Some people proposed not responding to the consultation in protest against the limited options but the MP warned silence could be taken as assent.

Peter Gray of Mark Parish Council advised No Moor Pylons to reflect Mark Parish Council's opposition to both corridors as they want any new pylons to go up alongside the M5.

Tessa Munt revealed there are 36 properties along the M5 between Seabank station in Avonmouth and Bridgwater and Loxton Gap.

Jeanette Shepherd of Mark said: "We don't want it in our backyard or for other people. But there are two people in Mark who have existing power cables in their properties and are in remission of leukaemia.

"I was told at a National Grid consultation that in places like schools the lines could go underground. If there's a health issue why not put it all underground?"

Mr Heathcoat-Amory said it was concerning and there were conflicting studies of electromagnetic fields causing leukaemia and he would do his best to keep lines away from houses and schools.

The corridor choice stage of the consultation ends on January 8, 2010.

David Heathcoat-Amory will be taking questions at Mark Village Hall on Sunday at 5pm. All are welcome.