The world will take less notice of the United Kingdom if Scotland votes for independence, former Conservative Chancellor Ken Clarke has told his party's Scottish conference.
The UK Government's Minister without Portfolio told delegates in Edinburgh that the UK will also have "less say" in global affairs if it leaves the European Union.
Mr Clarke used his speech to emphasis the importance of open trading in the context of both the independence referendum and the potential vote on the UK's EU membership.
He said that currently the UK is one of the "key players" in the EU who can make a difference. The UK Government is also the "leading light" providing European access to emerging markets such as Brazil.
This has benefited Scotland, he said, with the country getting "the bulk" of multi-million dollar engineering contracts from the South American country.
He told the conference: "Were we to go with the separatists ... it would obviously take us away from tables - we wouldn't be allowed to sit at them. If we were allowed to sit at them it would be a bit like Malta, we would have to sit at the end and behave ourselves.
"Do you want people to take notice of Scotland, and as much notice of United Kingdom in 30 years' time?
"They'll take less notice of us if the Scots have left us, and we'll have less say as the United Kingdom if we have left the European Union."
Mr Clarke added: "I would feel diminished if Scotland left the United Kingdom. The English, Welsh and the Ulsterman do not wish to see Scots leave the union, and it is not just for all the practical reasons I have spelt out, it's for emotional reasons as well."
He said "ordinary, sensible, intelligent Scottish people" had become more engaged with the independence debate.
"If the bulk of ordinary, sensible, intelligent Scottish people vote I will feel all the more comfortable with the outcome," he said.