Insurance giant becomes latest to raise questions over independence

Now, I know this is starting to turn into something of a procession, but the latest chief executive to raise concerns about Scottish independence is the head of Aviva, Mark Wilson.

In the insurance giant's first substantive words on the subject, Mr Wilson told me that he was concerned that infrastructure funding - and that means the building of schools, hospitals and roads - could become more expensive.

Before today, Aviva has studiously stayed out of the debate. So the fact that Mr Wilson has chosen now to speak is significant.

"Other commentators have pointed out the challenges that the Scottish financial system will face in the event of a yes vote," Mr Wilson told the BBC.

"Aviva is a long-standing investor in Scottish infrastructure and we will maintain our commitment.

"However, the cost of borrowing to fund important public infrastructure, such as schools, hospitals and roads, would almost certainly go up, to cover the increased risk of being a smaller independent country."

'Investment grade'

The credit rating agency Moody's has said that an independent Scotland would be likely to receive an A rating - the key measure of how much a country has to pay to access investment from the international money markets.

Although that is what is known as "investment grade", and Moody's has made it clear it could rise over time, it is two levels below the present UK rating of Aa1.

That means that Scotland would have to pay more to access infrastructure funding from the likes of Aviva - which invests billions of pounds across the world, much of it funded by our pension pots.

John Swinney, the Scottish finance secretary, has said that "year-on-year, Scotland is in a stronger financial position than the UK as a whole".

He certainly believes that whatever the initial credit rating, it will improve on the back of the country's economic strength.

Mr Wilson makes it clear that how Scotland votes is not a matter for him.

'Impartial approach'

"Scottish independence is a matter for the Scottish people and it certainly is not for me to express a personal view," he said.

"There are many New Zealanders like me of Scottish descent but, notwithstanding this, I'm trying to approach this question impartially.

"Aviva is the UK's leading insurer and as its CEO I have a responsibility to our customers, our people, our shareholders and the communities in which we operate. I do believe, though, the Scottish people should make this important decision with full knowledge of the facts."

Mr Wilson points out that Aviva has 2,000 employees north of the border and has about a million customers.

It does not have the same challenges as Standard Life, which is domiciled in Scotland and announced last week that it was looking at setting up new businesses in England to ensure the 90% of its customers who live south of the border will still have all their transactions, pensions and savings denominated in sterling.

Perth headquarters

You can read all about Standard Life's contingency plans here.

Aviva is largely domiciled in England. One of its businesses, General Accident, may have its physical headquarters in Perth, but its all-important licence is held south of the border.

"Protection, savings and investment are fundamental to the economy," Mr Wilson said.

"Aviva's heritage is both English and Scottish in the form of Norwich Union, Commercial Union and General Accident, a Perth headquartered operation, which remains as vibrant today as in the past."

If an independent Scotland does receive a credit rating of A, then funding costs will increase. It will be up to the new government to convince the markets that Scotland's economy is a positive place to invest.