Uncertainty surrounding a future independence referendum is damaging the Scottish and UK economy, the Chief Secretary to the Treasury has claimed. Danny Alexander has become involved in a war of words between Westminster and Scots Finance Secretary John Swinney. Mr Swinney has accused the UK government of talking down Scotland. In a letter to Mr Swinney, Mr Alexander said the last thing needed was \"a self-inflicted wound by the Scottish government\". Last week, the Chancellor claimed instability caused by the planned referendum was damaging investment in Scotland. Mr Swinney said he was happy to have an evidence-based debate, but there was no evidence coming from the coalition government. In his letter, Mr Alexander said: \"The uncertainty created by the Scottish government is damaging not just Scotland but the whole of the UK. Continue reading the main story ,It would be helpful if the Scottish government ... took urgent steps to deal with this issue” Danny Alexander Chief Secretary to the Treasury \"At a time when there are severe headwinds facing the whole UK economy, the last thing the UK needs is a self-inflicted wound by the Scottish government.\" The Chief Secretary to the Treasury said it was \"ridiculous\" to suggest the UK government was in some way trying to harm investment in Scotland. He raised concerns from a Citigroup report and from CBI Scotland about investor caution and uncertainties arising from the timing of a referendum. The SNP aims to introduce a referendum bill later in its five-year term. Mr Alexander concludes: \"We will continue to do all we can, within difficult fiscal constraints, to support economic growth in Scotland. \"But it would be helpful if the Scottish government recognised that its core policy commitment is causing real uncertainty and took urgent steps to deal with this issue.\"