AN invasive plant blanketing a Lake District tarn has been branded a 'serious hazard.'

There is concern that unwary hikers on the popular 'coffin route' between Grasmere and Rydal could inadvertently walk on to White Moss Tarn and get into difficulties in the water.

Sharon Savasi, of the Grasmere Village Society (GVS), feels something needs to be done urgently by landowners Lowther Estates to get rid of the danger.

"Because of the pygmyweed it now looks like solid ground and there is a real danger that somebody will walk straight into it and get into difficulties," said Ms Savasi. "Unfortunately the National Trust no longer manage this area as the landowners Lowther Estates have taken it back under their management. I have contacted Lowther who assured me they would look into the matter.

"Three months later I contacted them again as nothing had been done, as yet I've had no response.

"Even a warning sign or some tape to alert people to the possible danger would be better than Lowther completely disregarding their responsibilities.

"We are now coming up to another season when tourists will once again be walking in our delightful part of England. I feel very frustrated and cross that I and the GVS have been ignored."

Andrew Fox, an agent of Lowther Estate, said he had been informed of the issue, but added there was currently no time frame on when it would be resolved.

"We are aware. We are currently looking at what we can do to clear it," he said. "We are taking steps to deal with it but we do need various consents. We manage a vast area of land and there's various things coming up and we have just got to prioritise them as we see fit."

New Zealand pygmyweed is a yellowish-green perennial that tends to grow in ponds, lakes, reservoirs, canals and ditches. Due to its invasive nature and its tendency to form dense patches of vegetation on water surfaces, it shades out other plant species and can lead to a lack of oxygen in water affecting aquatic wildlife.