DEPUTY First Minister John Swinney has pledged the SNP Government will do everything it can to prevent the closure of the coal-fired Longannet power station.

The Fife plant is due to shut by the end of March next year unless it secures a short-term National Grid contract, raising concerns over the security of Scotland's electricity supply.

A decision on the contract, which is to help maintain voltage levels in the electricity supply from April 2016 to October 2017, is expected laterthis month.

Mr Swinney, who is to visit the site today (Mon), said:"Longannet plays a key role in security of electricity supply, voltage control and 'blackstart' capability as well as supporting over a thousand jobs and benefiting the Fife and wider Scottish economy.

"The Scottish Government is determined to do all that we can to avoid the premature closure of Longannet and our dialogue with National Grid and the UK Government has been focused on that objective."

Scottish generators, including Longannet, account for around 12per cent of the capacity connected to Britain's high-voltage electricity network - but pay around 35per cent of the charges, according to the Scottish Government.

The SNP claims that National Grid say that proposed changes will reduce charges by one third but points out that Longannet's charges are forecast to increase from £40 million this year to £51 million in 2017 and 2018.

The ScottishPower-operated coal-fired station is under pressure from new European Union environmental legislation and carbon taxation combined with higher transmission charges to connect to the grid due to its location in Scotland.

Neil Clitheroe, chief executive of retail and generation at Scottish Power, told Holyrood's Economy, Energy and Tourism Committee last week that the company had hoped to keep the plant going to 2020 but even if it were to win the National Grid bid it would only provide the plant with a year or two's grace.

WWF Scotland director Lang Banks said: "It is now very clear that thanks to the massive growth in Scotland's renewable power output and planned upgrades to the transmission network, the lights will not go out when Longannet eventually closes before the end of the decade."