Walkers and climbers heading for Scotland’s Western Isles will soon benefit from reduced ferry fares.

Six routes have been chosen to pilot a scheme which will mean travellers pay only the equivalent of a road journey of similar length. The Scottish Government will subsidise the nationalised Caledonian MacBrayne ferry operator to the tune of £22.5m during the scheme, which will start this autumn and run until spring 2011.

The road-equivalent tariff (RET) fares mean, for instance, the present £15.30 one-way foot passenger fare for the crossing from Ullapool to Stornoway on Lewis will be cut to £7.22. Cars and small vehicles will be charged at the rate of £5 plus 60p a mile. Fares for some passengers will be halved.

High fares have been blamed for deterring visitors from travelling to the Hebridean islands. Harris in particular has prime walking country, boasting one Corbett, Clisham. Mull has one Munro, Ben More, but many of the islands offer remote walking in unspoilt country.

Skye, famed for the Cuillin range, can be reached by the Skye Bridge, but ferries leave from Uig, near its main town Portree, for Tarbert on Harris.

Routes earmarked for the pilot scheme, in addition to the Stornoway sailing, are: Uig to Tarbert and Lochmaddy, North Uist; Oban to Castlebay, Barra, and Lochboisdale, South Uist, and Oban to Coll and Tiree. The scheme starts on 19 October this year.

But the plans have caused political controversy, with Orcadians and Shetlanders aggrieved that the Northern Isles have been excluded. Politicians say the Western Isles have been favoured because they have a Scottish National Party MP and MSP.

Liberal Democrat Tavish Scott, the MSP for Shetland, told The Scotsman: “This is blatant discrimination. Reducing ferry fares to help island economies is the right approach, but this pilot is expected to last for three years and only targets one Scottish island group.

“The SNP government is essentially operating a permanent scheme in one part of Scotland, but not in the equally deserving other island groups.

“People here are slightly wondering: 'Is it to do with the SNP hold on the Western Isles?' Because if that were the reason, that’s not a good reason to base policy”.

Residents of Scotland’s islands already benefit from special Islander fares.

The Scottish Government said if the RET scheme was successful, it would be extended to other island routes.