Scotland should roll out the red carpet to rich people, scientists and engineers by keeping taxes low and lifting the ban on GM crops and fracking, Scottish Conservative leader Ruth Davidson said.

The Scottish Government should pledge never to raise taxes higher than the rest of the United Kingdom to prevent Scotland's already low proportion of top-rate taxpayers fleeing south, she is expected to tell an audience in London.

She attacked Scottish Labour leader Kezia Dugdale's "utterly naive and self-defeating" plan to levy a 50p top rate of tax on people with salaries of more than £150,000.

Scotland had just 14,000 top-rate taxpayers, about five per cent of the UK total and below its population share.

Ms Davidson wants to attract another 10,000 high earners to contribute hundreds of millions of pounds towards public services.

In advance extracts of a speech to the Adam Smith Institute at Westminster, Ms Davidson said: "We do that first by guaranteeing that tax rates in Scotland will be no higher than the rest of the United Kingdom, something I urge the Scottish Government to do immediately.

"This sends out the right message to everyone from across the UK that Scotland is not about punishing earned wealth.

"Secondly, I want to see us in Scotland rolling out the red carpet to our neighbours across the United Kingdom."

She added: "There is a problem, in that the SNP government keeps sending the wrong messages.

"Politics is all and the SNP's interest lies in continually trying to find a wedge to drive between us and the rest of the UK.

"Two weeks ago, the SNP made the entirely populist decision to ban GM crop development in Scotland.

"Will a well-paid scientist or bio-tech expert bring her family to Scotland now? I doubt it.

"Over the summer, the SNP - egged on by Labour - set out an equally populist ban on fracking technology. Will that encourage engineers to come and find opportunities in Scotland? I fear not.

"I know from speaking to business leaders at home that there are real worries that we are missing out of this great British revival."

She continued: "Scottish Labour's new leader Kezia Dugdale was barely in the job a week before stating her desire to raise taxes on middle to high earners.

"This, of course, will receive the warmest welcome from George Osborne as its most immediate impact will be to encourage Scotland's top-rate taxpayers to leave Scotland for south of the border.

"It is Labour at its most typical: borne of legitimate intentions, but utterly naive and self-defeating."