SNP leader and Scotland's First Minister Nicola Sturgeon believed that if she was to adopt a new 50p for additional rate tax payers then Scotland could lose up to £30m a year.

However, she told BBC Radio Scotland's Good Morning Scotland programme that she would not rule out an increase in the future.

Speaking to presenter Gary Robertson, Ms Sturgeon said: "I will task the council of economic advisers to look at this on an annual basis to determine whether or not there are ways in which we can mitigate that risk.

"It makes no sense to propose a tax measure knowing that it might reduce the amount of revenue we have to spend on our public services.

"We will judge it on a year by year basis."

Ms Sturgeon was speaking at the start of her party's election campaign.

Voters go to the polls on 5 May to elect their next MSPs.