SCOTTISH Secretary Alistair Carmichael will today unveil a "top 20" list of reasons why Scotland should stay in the UK, as he launches a new bid to present a positive case for the Union.

The Liberal Democrat minister will outline arguments the No campaign hopes will appeal directly to voters heads and hearts in the run-up to the poll on September 18.

Mr Carmichael's list of key benefits, to be outlined at Stirling University, includes the UK-wide currency, safer banks, cheaper mortgages, greater public spending per head in Scotland and more than 200 shared institutions including the BBC and Met Office.

He will also make an emotional plea for Scots to back the UK, adding: "Our commitment to the UK family is not just about the facts and figures, it's also about the values and ambitions we share."

Mr Carmichael's first major speech of 2014 marks a new phase in the campaign for a No vote, putting greater emphasis on the positive case for staying in the UK.

It comes after weekend interventions in the independence debate by former Prime Minister Gordon Brown and shadow international development secretary Jim Murphy, confirming promises Labour's most senior Scottish MPs were poised to become more deeply engaged.

The Scotland Office's new "top 20" list is based on Whitehall's Scotland Analysis series of in-depth studies assessing the likely impact of independence. It claims sterling is the "strongest currency option" for Scotland and warns independence would not guarantee continued use of it.

It claims banks are safer as part of the bigger UK and also highlights public spending of £1364 per person more in Scotland than the UK average. Other claimed benefits include cheaper mortgages, defence jobs and "world class" security services.

Mr Carmichael will highlight what he will call "clear cut" benefits, but he will also attempt to inject some passion into the pro-UK case by citing Team GB Olympic heroes, and institutions such as the NHS and BBC.

He is expected to say: "Let no-one underestimate what we share. The hands that built the United Kingdom have created things of enormous value. Why should we now break these things up? By staying together, we can build on those values to create a strong and secure future."

Mr Carmichael will promise to keep making for the remainder of the campaign the "positive case" for Scotland staying in the UK. This follows repeated complaints from the SNP that the No campaign has been dominated by "negative" attacks.

Meanwhile, Labour former secretary of state for Scotland Jim Murphy urged Scots to reject the SNP's argument that independence was the best way to remove the Conservative-Liberal Democrat Coalition at Westminster.

Looking ahead to the 2015 Westminster election, the East Renfrewshire MP wrote: "The truth is that Tory policies are a poison that Scotland doesn't want to, and doesn't have to, drink."

Deputy First Minister Nicola Sturgeon said: "The Scottish Government has published Scotland's Future, which outlines in comprehensive detail the clear, transformational benefits of becoming an independent country."