The firm behind plans for an £1.8 million activity hub plan at Thirlmere has defended the scheme.

Treetop Trek want to install two zip lines and an 18km cycleway in the managed forestry around the reservoir.

The lines would stretch from one side of the lake to the other.

The plans have attracted a huge amount of opposition from Friends of the Lake District and the Open Spaces Society, among other groups, and thousands of people have signed a petition against it.

They say it will ruin the area's tranquil nature.

But Mike Turner, managing director of Treetop Trek, told the Financial Times: "The Lake District is not just for mountain climbers and fell walkers. It is for everyone. It shouldn’t be preserved in aspic."

Mr Turner said the Thirlmere Activity Hub will create the equivalent of 28 full-time jobs and attract an extra 127,000 visitors a year.

Television star Caroline Quentin is also against the plan. She said: “My fear is that they will spoil the peace and tranquillity of this beautiful, important place. I am all for development that enhances our national parks but my instinct is that we should say no to zip wires in Thirlmere.”

Filmmaker Terry Abraham resigned as ambassador for The Lake District Foundation, formerly Nurture Lakeland, in protest against the charity’s neutral stance on the application.

The scheme has also received backing, with supporters including Cumbria Tourism and the Lake District Park Partnership Business Task Force.

Mr Turner said: "Zip lines and cycle tracks are clearly not environmental matters – they are emotional ones.

"This debate is rapidly and sadly becoming about who should be using the landscape and what they should be doing in it. I for one want to see more people enjoying it."

The closing date for comments on the plan has been extended to January 12.