JACKMcConnell must publicly rule out new nuclear power, opposition MSPs said yesterday, after news that a reactor at Hunterston in Ayrshire is to be shut because of safety fears.

The SNP said the credibility of building nuclear power stations in Scotland was in tatters, while LibDems called for investment in renewables.

British Energy is preparing to shut reactors at Hunterston and Hinkley in Somerset, after an inspection at a Hinkley plant found cracking.

Following the announcement, Richard Lochhead, SNP environment and energy spokesman, said: "This is further evidence that nuclear power is not only dangerous and dirty but also unreliable. It is not only the pipes at Hunterston that are cracking but Mr McConnell's evasive nuclear policy. New nuclear power is totally unnecessary in a country such as Scotland, which has vast renewables potential."

Mr Lochhead claimed the First Ministerwas endangering Scotland's future by refusing to take a firm stance on the issue.

Scottish Liberal Democrats said the closure at Hunterston underlined the need for investment in clean energy, specifically wave power and microrenewables.

A spokeswoman said: "The Liberal Democrats have always been against new nuclear for Scotland as it is unsafe, unwanted and uneconomic. This incident only reinforces the case for moving to green, renewable technology for our energy supply."

A spokesman for the First Minister said no decision had yet been taken on whether to build new plants.

He said: "Our position has not changed: there will be no new nuclear power stations until the issue of nuclearwaste is resolved."

Scottish Tories rejected calls to rule out nuclear power. Alex Johnstone MSP, environment spokesman, said: "We need to keep all our options open. If nuclear is cost-effective it may be justifiable as part of a balanced range of energy sources.

"The fact that responsible decisions have been taken at Hunterston simply underlines the exemplary safety record of the Scottish nuclear industry."