The United Kingdom's constitution is "unsustainable" and risks tearing the country apart unless it adopts a federal system, according to a commission led by a veteran MP.
A Declaration of Federal Union is the only way to combat Scottish independence and UK regional inequalities, the commission led by former Liberal Democrat leader Sir Menzies Campbell has concluded.
Scottish Lib Dems asked Sir Menzies to devise a system of "home rule" for Scotland as an alternative to independence, but his final report released on Wednesday expands the theme to "home rule all round" the UK.
The commission recognises that there has been little appetite for home rule for England, but insists that recent constitutional developments such as devolution and complaints about Scottish MPs voting on purely English matters - the so-called West Lothian Question - has led to a growing awareness of the need for a shake-up of the system.
The Scottish National Party is holding a referendum on independence in 2014, promising "a more equal relationship between the people of these islands".
Lib Dem MP Michael Moore is leading negotiations on the independence referendum for the UK Government as Secretary of State for Scotland.
Sir Menzies said it was "nonsense" to believe Scottish independence could remedy inequalities across the UK.
"I don't think the present constitutional arrangement is sustainable," Sir Menzies said at the launch of the report.
"We've got the West Lothian Question, but we've also got the West Belfast Question and the West Wales Question."
The commission states that the new federal relationship "amounts to nothing less than a remodelling of the United Kingdom for the modern age".