Fears that Scottish independence could reopen divisions in Ireland have been dismissed by former Northern Ireland Secretary John Reid.
Mr Reid said the Scottish referendum does not have "a particular implication for Ireland", in response to concerns by Swedish foreign minister Carl Bilt, who said independence would lead to the "Balkanisation" of the UK.
He accused First Minister Alex Salmond of running a Monty Python-esque campaign by deliberately ignoring the benefits of the UK and the risks of independence.
Mr Reid, also a former Scottish Secretary, welcomed the fact that all political parties are now committed to improving devolution "if necessary".
"I think Scotland and Ireland are two separate issues," Mr Reid told the Press Association ahead of a Better Together speech in Stirling.
"Personally I welcome the fact that in recent years there has being a growing rapprochement between the governments of the UK and Ireland.
"I am very proud to have played a small part of that when I was Irish Secretary and in other cabinet posts.
"I think in doing that we are helping to make up for some of the mistakes of history.
"So, at a time when there is, in a sense, a coming together after so many years, indeed centuries, of the UK and Ireland, I think it would be paradoxical if Scotland was to separate from the rest of the UK at precisely that time.
"I don't think it has a particular implication for Northern Ireland.
"If the UK breaks up it will have wide repercussions outside the UK. When the President of the United States says that, it's an indication of the difficulties.
"When the prime minister of Spain, the president of the European Commission and the foreign ministers of the Scandinavian countries say that, it's an indication that they are concerned about the wider implications of it."
He added: "All the major parties are now committed to looking at the details of the constitutional settlement and improving it if necessary.
"Life is constantly changing. I constructed the devolution plan that is now in place with Gordon Brown and others.
"But if there is sense in looking again at this, as all the major parties now think, that is something that I would support.
"It may need to bring together some kind of convention or discussion amongst all the other parties to see what has the widest possible support."
During his speech, Mr Reid said: "We have been going through a sort of Monty Python period of exchange.
"Every time I hear the SNP respond to an argument it reminds me of the sketch: 'What have the Romans ever done for us?'.
"What has the UK done for us? Well, it gave us financial stability from the period after the Darien Scheme when Scotland was very badly affected by a catastrophic economic mistake through to a few years ago when RBS ended up with toxic debt greater than the GDP of Scotland.
"They, say: 'Well, I give you that - but what has the UK ever done for us?'."
He added: "It is possible to look at an elephant and swear that there is no such animal, but it doesn't make it a reality.
"The more the Scottish Nationalists say that ratings agencies don't know anything about ratings, that the governor of the Bank of England doesn't know anything about sterling, that the president of Europe doesn't know anything about Europe, that the Institute for Fiscal Studies doesn't know anything about fiscal studies, that economic experts don't know anything about economics, you begin to think that however sincere Alex Salmond's commitment is his pursuit of his own objectives are blinding him to reality.
"We got rid of the divine right of kings and we are not about to restore divine wisdom to Alex Salmond who can, by decree, suspend reality."
Scottish Health Secretary Alex Neil described Lord Reid as a "Labour failure" who is part of a system where "all the money goes to London and we are left with the petty cash in Scotland".
A No vote would be "horrendous" for the Scottish people, he said at a Yes Scotland rally at Strathclyde Country Park, Motherwell.
"Today we had another Labour failure Lord John Reid telling us that staying with Britain would be safer than an independent Scotland," he said.
"Does he not realise that the source of the threats to the UK arise because him, Tony Blair and Gordon Brown and all their cronies took us into an illegal war in Iraq?
"One of the big advantages of being independent is that we will not go into illegal wars in Iraq or anywhere else and we will get rid of the weapons of mass destruction in the Clyde, and that will certainly never happen as long we are ruled from London.
"The reality is if we vote No the consequences for the Scottish people are horrendous."
He added: "If we vote No, we will never be taken seriously in London ever again.
"Don't believe all these promises of new powers for the Scottish Parliament. We have been down this road before and the last time the Scottish people bought that we ended up with 18 years of Thatcher and John Major."
He continued: "Gordon Brown says we have got to vote No so we can pool our resources with the rest of the UK.
"Does Gordon Brown not realise that what they mean by pooling resources is that all the money goes to London and we are left with the petty cash in Scotland?
"In 13 years as Chancellor and Prime Minister he had the opportunity to show us that Britain works for Scotland, and even Gordon Brown couldn't make Britain work for Scotland."
"Under Gordon Brown the rich got richer and the poor got poorer."