LEADING conservation groups are asking Scottish Secretary Donald Dewar to make Scotland's new Parliament building green and clean.

Among the features proposed by the Scottish Wildlife Trust - whose patron is the Prince of Wales - and Friends of the Earth, Scotland, are solar heating, recycled materials and staff being encouraged to cycle to work.

They also want bird nesting boxes incorporated into the building's walls, heat reclaimed and recycled from expelled air and waste water during winter - and a regular environmental audit of the building's green performance.

In a joint letter to the Minister, Nigel Doar, campaigns co-ordinator for the SWT, and Dr Richard Dixon, head of research for FoES, say the new building must ''lead the way in environmental standards for new construction.''

''We hope very much that the environmental impacts used in constructing the Parliament building will be taken into account when deciding between different possible designs,'' they say.

''The use of timber from sustainably managed sources, the appropriate use of recycled materials, and the use of materials from sources as near to Edinburgh as possible, would be desirable.''

The groups also want an integrated public transport system that does not rely on getting to the building by motor car. They also want showering and changing facilities in the new Parliament to encourage staff to cycle or walk to work - as well as a new railway station at Holyrood.

The groups say that they want to see as much green space as possible around the building, not only for people to relax in and wildlife to flourish, but good tree planting will also increase energy efficiency and filter pollution from the air.