An independent Scotland would lead to a weaker Britain and work against Australia’s national interest, according to former Foreign Minister Alexander Downer.

Speaking to the Australian Financial Review, Mr Downer said the breaking-up of the United Kingdom would damage Britain’s international standing, a poorer outcome for Australia.

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An estimated 90 per cent of Scots have registered to vote in the historic independence referendum on September 18, which if successful would have significant financial ramifications across the UK.

“It will be a very big setback for Britain if Scotland hives off,” Mr Downer said.

“Can Australia be neutral about that? We are only really interested in Australia’s national interest.”

“And because of the strength of our relationship with Britain, and because of our relationship with Britain, and because of the like-mindedness of Britain with Australia and because of the way Britain is always so willing to help us promote our national interest – a weaker Britain is a poorer outcome for Australia,” he said.

Mr Downer, who is Australia’s High Commissioner to the UK, said he supported Prime Minister Tony Abbott’s comments that supporters of the yes campaign were “not the friends of justice or freedom.”

“If Scotland were to hive off from the United Kingdom then the not-so United Kingdom will, I think, lose a lot of prestige and will be weaker internationally than it currently is,” Mr Downer said.