The extension of Hunterston B's licence to generate nuclear power is more of an engineering matter than a political one. But it won't stay that way, and the boss of the company that owns the plant wants to meet Alex Salmond to make the case for a replacement.

It is for a UK-wide licensing authority to make the decision on whether it is safe to keep a reactor operating beyond its designated lifespan.

But it is for the Scottish Government to decide if Hunterston - or the other two licensed Scottish sites at Torness in East Lothian and Chapelcross near Dumfries - can be replaced with new plants. The law gives the Scottish Government the powers to grant or withhold permission under both planning law and a special measure under the Electricity Act.

Those backing nuclear say it is necessary to stop the lights going out, and that renewable generation cannot fill the gap. Its critics point out that Hunterston's technical difficulties have meant it has supplied only a small share of Scotland's electricity over recent years. With Chapelcross now closed, of more significance is Torness, which is due to operate until 2023.

The SNP has been a long-time opponent of nuclear power. And while it is not in favour of shutting existing plants, it represents an obstacle to the building of new ones. LibDems are similarly opposed, while Labour is split.

Conservatives in Scotland were keen to replace Chapelcross but that changed under David Cameron. The nuclear option has become a lower priority for the party, with more emphasis on a big push for renewable energy.

Bill Coley, chief executive of British Energy, said yesterday there is land for new plants at Hunterston and Torness but it would only build new facilities where there is support for doing so.