TENSIONS between nations are being fostered by fears of a break-up of the United Kingdom, Neil Kinnock warned yesterday.
The former Labour leader said the devolution of powers at different paces across Britain would lead to misunderstandings and enmity between the nations and the regions.
His comments come just three weeks before Labour closes its public consultation on giving more powers to the National Assembly to scrutinise legislation.
Lord Kinnock was speaking at the Scottish Parliament as Scotland's first Festival of Politics began in the Holyrood building.
The former European Commissioner, who is now chairman of the British Council, said he was not against decentralisation but warned the fragmentation of Britain could breed "enmity".
He said, "What continues to concern me is not decentralisation of effective administrative and executive power but the fear, and the fear still exists, of the fragmentation of the United Kingdom and the possibility of enmity growing out of it."
Lord Kinnock added, "Unless there is a general pattern of decentralisation throughout the whole of the United Kingdom, the possibility of tensions, misunderstandings, even antagonisms between the different parts of the United Kingdom, continues."
He has already promised to campaign for a "No" vote in the unlikely event that Welsh Labour sanctions a second referendum on more powers for the National Assembly.
Labour's White Paper Better Governance for Wales includes proposals for a referendum but is vague about the level of public demand which would be required for such a referendum to be launched.
Welsh Secretary Peter Hain has set his face against a public poll, warning Welsh people have no appetite for it.
Instead the Government of Wales (Amendment) Bill, due to be introduced in Parliament late this year or early in the next, will propose fast-tracking Welsh legislation through Westminster but rules out law-making powers for Cardiff.
Opposition parties said Lord Kinnock's comments highlighted real differences within Labour over devolution which had forced the Welsh Secretary into a compromise deal on the next stage of devolution for the National Assembly.
Shadow Welsh Secretary Bill Wiggin said, "I don't generally find myself in agreement with Lord Kinnock but we are both basing our concerns on what has happened.
"If Wales had, for example, a fantastic record of delivery since devolution then Lord Kinnock would not be able to say these sorts of things.
"The real reason that people still worry about devolution is because they worry about the health service, they worry about delivery of the public services.
"Everything the Assembly has got powers to control, they have major worries about."
But Plaid Cymru's Shadow Social Justice Minister Leanne Wood branded Lord Kinnock an "unreconstructed anti-devolutionist" who had "never adjusted to the fact that people in Wales want to take decisions for themselves".
She added, "We deserve equality with England and Scotland.
"Equality will not create enmity but the current unequal devolution settlement could.
"It is giving Wales a second class institution that creates resentment not the process of devolution itself.
"We want a Parliament for Wales that can deliver real change for its people, not a talking shop Assembly which serves nobody except New Labour."
Ms Wood said it was clear the current settlement was not working for Wales but branded Welsh Labour "utterly divided" on devolution and bent on frustrating the will of the majority for a Welsh Parliament.
She added, "It is up to the people of Wales to decide how they want to shape their nation's future - something that Neil Kinnock will never understand.
"This is far too important a matter to be left to a few self-serving, anti-Welsh antediluvian Labour peers in London to decide."
The Electoral Commission has used the three-day Festival of Politics to raise concerns of public disengagement.
Electoral Commissioner Sir Neil McIntosh said, "We know that many people find the formal language of the political process alien and off-putting.
"By using plain language we can demystify politics and help people make the connection between the issues they care about and getting involved in our democracy."