It is nearly four years since the Cairngorm National Park came into being, but motorists on the A9 are still not officially informed when they have entered its southern fringes. A sign on a large granite block is planned for the Drumochter Pass near Dalwhinnie, but has not yet been erected.

For campaigners south of that point, who want to redraw the park's boundaries, its continued absence offers hope, but is also a metaphor for their struggle to win a rightful place within the park: ministers putting in their way obstacles which do not exist.

The feeling was a recurring theme in evidence given yesterday to MSPs on the Scottish Parliament's environment and rural development committee, meeting in Blair Atholl.

John Swinney has moved a bill to extend the boundaries of the park southwards, to embrace Highland and East Perthshire, as was originally recommended to ministers by Scottish Natural Heritage (SNH) in 2001.

But the Scottish Executive is opposed, believing all matters relating to the governance of the park should wait until the quinquennial review, which is due to start in 18 months.

Even SNH said it was not convinced of the case for change now. "While we believe that the reasons put forward at that time remain valid, we have concerns that changing the area of the park now may distract the park authority from its key task of implementing its first park plan," it said in written evidence.

However, Mr Swinney and the numerous community bodies which gave evidence yesterday to a packed audience believe that to wait for the review would delay the change until 2012.

The issue of the granite block arose during evidence given by Jane Hope, Cairngorm National Park Authority chief executive. She said it had been calculated to move the boundary as suggested in Mr Swinney's bill would involve additional costs: £100,000 a year for additional staff and travel, and a one-off cost of £150,000.

Under questioning from Mr Swinney, Ms Hope said perhaps as much as half of that one-off cost would be from moving the signs from the existing southern boundary to the boundary proposed by Mr Swinney, just south of Blair Atholl. She conceded this would involve only smaller signs on a couple of minor roads, and the big one on a granite block in the Drumochter Pass.

All local representatives wanted Blair Atholl to be the southern gateway, not Dalwhinnie. Insult had been added to injury, they said, when they had tried to put up a sign calling Blair Atholl the Gateway to the Cairngorms, only to told by officialdom to take it down because the village was 18 miles from the park's boundary.

Professor Ian Brown, of Queen Margaret College, Edinburgh, representing the Pitlochry Partnership, said: "The legislation may have created the park, but it can't turn an elephant into a mouse.

"Here in Blair Atholl we are just 800 yards away from the Cairngorms. If you go north from here, you don't come to Dalwhinnie. The A9 goes to the west specifically because the Cairngorm Massif was blocking the way. Blair Atholl is the natural gateway to the Cairngorm National Park."

Lin Muirhead, chairwoman of the Blair Atholl Area Tourism Association, agreed. "Blair Atholl is the main historic and natural gateway to the Cairngorms from the south. With five historic routes from the village north into the Cairngorms, it holds a position not emulated by any other town or village. Anyone in Dalwhinnie wanting to walk these routes would have to come back down to Blair Atholl to start."

After heading north from the village by train or car, travellers did not meet another village of comparable size or facilities until Newtonmore and Kingussie.

Many of the local groups who gave evidence saw great economic advantage in being within the park's boundaries, particularly in tourist-related activities. But the present boundaries offended others' sense of what the Cairngorms are, not least Dave Morris, director of Ramblers Scotland.

He won applause by calling on ministers to instruct officials to begin work on new boundaries within two or three weeks, saying the decision to omit Highland and East Perthshire was "absurd" and needed to be corrected at the earliest opportunity.

"Every authoritative report on the Cairngorms, from the 1960s onwards, which has examined the qualities of the Cairngorms and future requirements for their protection, use, and enjoyment, has focused on a large area, including substantial tracts of Highland Perthshire extending as far south as Blair Atholl," he said.

"The Cairngorms are re- nowned, across the world, for their remoteness, rugged terrain and weather, and relative absence of buildings and roads. They contain the most remote land in the UK.

"Unfortunately, the present southern boundary splits this area in half, leaving large tracts of mountain land and unspoilt river systems outside the park."

Nigel Hawkins, director of the John Muir Trust, appealed to the committee to think in an international context. National parks in countries like North America, where Scotsman John Muir had pioneered the wilderness conservation movement, had always gone for large naturally defined areas, he said.

"When I take visitors from abroad up into the Cairngorms they can't understand why there is a hole created by the boundary."

Mr Swinney's bill would also mean that the Spittal of Glenshee would be embraced by the park, providing a smaller gateway from the east, before visitors reach the Glenshee ski slopes. This was supported by community groups there.

The committee is expected to deliver its report next month.