THE future face of the central Highlands will come under the spotlight this week, as a Holyrood committee and a planning inquiry begin their considerations of national park boundaries and giant electricity pylons.

The hearing into the Beauly/Denny power line, which would cut right through the national park, opens in Perth and is set to surpass even the Harris superquarry which was the subject of Scotland's longest-running planning inquiry to date.

In a separate forum touching on the region's future, MSPs will today take evidence in Blair Atholl from those calling for the extension of the Cairngorms National Park boundaries to embrace Highland and East Perthshire.

The 400,000 volt transmission line is necessary to transmit all the extra power which is expected to be generated by renewable energy projects such as wind farms in the Highlands and Islands. But those concerned by its impact are calling for the line to be put under ground.

Under the proposal submitted to the Scottish Executive by Scottish and Southern Energy (SSE) and Scottish Power, there will be 600 pylons, 200 fewer than the existing 132,000-volt line. But they will be up to 213ft high, compared with the Scott Monument's 200ft.

Meanwhile, the 12,000 pages of evidence produced by the developers for the inquiry has become legendary amongst the 18,000 objectors, which include Highland, Perth, Stirling and Falkirk councils and the Cairngorms National Park Authority.

The Scottish Executive is opposed to the extension of the park's boundaries and insists that it should be left until the review of the park's first five years of operation which is due in 2008.

But John Swinney, the SNP MSP for North Tayside, fears that this review will not tackle the issue of boundaries, or if it does, any change could take as long as till 2012 to implement.

So in September he introduced The Cairngorms National Park Boundary Bill. Holyrood's Environment and Rural Development Committee has been designated as the lead committee for stage one scrutiny of the bill and will hear evidence in Blair Atholl today.

The bill proposes that the park boundaries include the Forest of Atholl, and the community of Blair Atholl, the Beinn Udlamain mountain group to the west of the A9, an area around the A93 including Glas Tulaichean and the Spittal of Glenshee but excluding the village of Kirkmichael.

Mr Swinney says these areas were originally supposed to be in the park. In 2000 ministers had asked Scottish Natural Heritage to consult on their proposal to establish Scotland's second national park in and around the Cairngorms Mr Swinney said: "SNH recommended the park should include the Central Cairngorms and Lochnagar massifs and many of the straths which immediately surround them in Badenoch and Strathspey, in Glenlivet, in Donside and Deeside and, crucially in the south, in my constituency, the Angus Glens and Highland Perthshire."

Bill Wright, chairman of Perthshire Alliance for the Real Cairngorms (Parc), said yesterday: "Apart from a few politicians I don't know anyone who supports the present boundaries. They simply don't make sense. You can stand on a summit and have one foot in the Cairngorms National Park and one outwith it."