The "brightest and best future" for higher education in Scotland is to remain in the UK according to a group of former university principals.

In a joint statement, nine former principals from Glasgow, St Andrews, Edinburgh, Strathclyde, Edinburgh Napier, Stirling, Aberdeen and Paisley, now West of Scotland, have expressed their support for a No vote in the independence referendum.

The academics said there are two "fundamental risks" which will arise from leaving the UK.

"The first is to research funding available to Scottish universities from UK wide bodies like UK Charities and UK Research Councils," they wrote.

"As part of the UK our funding will reach as high as our excellence allows, not as far as the budget stretches. If we leave the UK then we put this hard won additional funding at risk.

"The second important risk is also to the funding of our universities in the form of tuition fees from students in England and Wales.

"The Scottish Government propose to exclusively charge English and Welsh students tuition fees if we leave the UK and join the EU. EU legal experts, the European Commission and the former Director of Universities Scotland have all said this policy would be judged illegal under EU law.

"Having analysed the evidence we can see no circumstances in which a separate Scotland could charge tuition fees to students from the rest of the UK. But we don't have to face this problem; it can be avoided by voting to stay in the UK."

They concluded: "Our considered opinion is that the risks and uncertainties of leaving the UK would very considerably outweigh any potential benefits. It is for this reason that we believe the best and brightest future for Scotland's universities is to remain part of the UK."

The statement was signed by Sir Graeme Davies, former principal and vice-chancellor at Glasgow University, Andrew Hamnett, former principal and vice-chancellor at Strathclyde University, Brian Lang, former principal and vice-chancellor at St Andrews University, John Mavor, former principal and vice-chancellor at Napier University, Andrew Miller, former principal and vice-chancellor at Stirling University, Sir Duncan Rice, former principal at Aberdeen University, Richard Shaw, former principal of Paisley, Sir David Smith, former principal of Edinburgh University and Lord Stewart Sutherland, former principal of Edinburgh University and former president of the Royal Society of Edinburgh.

The statement follows an open letter published last month in which a group of scientists and academics stated that Scotland's health and biomedical research interests will be better served by remaining in the UK.

The former principals' statement was welcomed by Better Together leader Alistair Darling.

He said: "The system of funding our universities in Scotland works well today because we pool and share our resources across the whole of the UK.

"We have some of the world's best universities right here in Scotland, which have flourished as part of something bigger. Where is the sense in putting that at risk?

"The nationalists can't just pretend that nothing will change if we vote to leave the UK. There are clear risks to our world-class research sector in Scotland. Wishing them away isn't good enough."

The Scottish Government has proposed the creation of a common research area to allow Scottish universities to continue to compete for UK-wide funding.

The SNP administration also intends to continue free tuition for Scottish students, while charging those from the rest of the UK.

It states that an "objective justification" for this policy can be put forward to address the EU rule which requires each member state to give citizens of any other member state equal access to its universities.

Professor Bryan MacGregor, speaking on behalf of the pro-independence group Academics for Yes, said: "The simple truth is that Scotland does well in open competition for funds but poorly where funds are allocated by other means, such as for research council centres and private research and development.

"The Scottish Government is committed to proper funding of research and other benefactors will support quality research wherever it takes place. Charities already raise substantial funds in Scotland."

He added: "On the one hand, we have the UK and England contexts of cuts in research and science funding, high student fees with unsustainable loan funding, an immigration policy that is preventing and deterring international student recruitment and the possibility of an exit from the EU and its research funding.

"And, on the other, we have a Scottish Government committed to funding research, to free access to universities for residents and to attracting international students. Independence will protect Scotland's universities and allow appropriate research priorities to be determined."

Over 100 academics declared their support for a Yes vote last month, stating a No vote would be a "threat to research".

The statement was signed by Prof MacGregor, vice principal at Aberdeen University, Prof Murray Pittock, the Bradley Professor of English Literature at Glasgow University, Prof Joe Goldblatt, director of the International Centre for the Study of Planned Events at Queen Margaret University, and Dr Stephen Watson, of Glasgow University, among others.

A Scottish Government spokesman said: "Scotland's Future expressly identifies objective justification as the basis for maintaining the current tuition fee arrangements in an independent Scotland.

"We are committed to maintaining current levels of Government investment for higher education research and with independence we will seek to agree maintenance of a common research area with the UK with shared Research Councils."