Britain risks becoming a 'failed state' unless it makes reforms to the union, former prime minister Gordon Brown has warned.
The former Prime Minister urged Boris Johnson to consider reforms like replacing the House of Lords with a 'senate of the regions' and to review the way the UK is governed.
Writing in The Daily Telegraph, Mr Brown said that 'the choice is now between a reformed state and a failed state', and the Government should use the Armed Forces and NHS to demonstrate the 'everyday benefits' of the union.
His comments come after The Sunday Times published the results of opinion polls in the four nations of the UK, which found a majority of voters thought Scotland was likely to be independent in the next 10 years.
In Scotland, the poll found that 49 per cent backed independence compared with 44 per cent against – a margin of 52 per cent to 48 per cent if the undecideds are excluded.
And Nicola Sturgeon branded Boris Johnson a coward as she threatened to hold a fresh independence referendum without his permission.
The First Minister said the Prime Minister 'fears the verdict and the will of the Scottish people' as she quoted the famous Robert Burns poem, saying he is a 'wee, sleekit, cowrin, tim'rous beastie'.
Mr Brown is one of the architects of the current political system in Scotland. He was chancellor when prime minister Tony Blair devolved powers to governments in Scotland, Wales and Northern Ireland in 1999.
The three now enjoy a range of powers to set policy in areas such as health, education, transport and environment.
In 2002, Mr Blair's government proposed bringing in elected regional assemblies for England with similar powers but the plan was rejected.
Britain risks becoming a 'failed state' unless it makes reforms to the union, former prime minister Gordon Brown has warned
A poll in the Sunday Times shows indicates a vote for independence would have the backing of the Scottish people and that a referendum should be held in the next five years
How the Union ended up on the brink of disaster after more than 400 years
James IV of Scotland becomes James I of England, after succeeding Elizabeth I. From this point on the nations have the same monarch.
England and Scotland are formally joined in the Act of Union.
The Scottish Nationalist Party is formed, calling for the creation of a separate Scottish assembly.
The SNP switches to demand secession from England, causing some senior figures to leave.
Following the discovery of lucratice oil fields in the North Sea, the SNP secures its first MP.
Tory PM Ted Heath responds to rising nationalism by committing to create a Scottish assembly. However, he does not follow through on the commitment.
James Callaghan's Labour government passes the Scotland Act, which laid the ground for a Scottish assembly to be established. However, a last-minute amendment made it a condition that at least 40 per cent of Scots back the idea in a referendum. Although the subsequent vote endorsed the change, the threshold was not reached so devolution did not happen.
Tony Blair and New Labour win a landslide, sweeping the Conservatives out of Scottish seats and promising devolution. Mr Blair hopes that giving more powers will halt the SNP's independence momentum. He puts Donald Dewar in charge of creating the new structure and holding a referendum.
Mr Blair's devolution push comes to fruition when Scots back creation of a Scottish assembly with tax-raising powers in a referendum.
The Scottish Parliament opens, with Alex Salmond saying it is a major step on the road to total separation.
The SNP secures a surprise overall majority at Holyrood, despite the electoral arrangements being designed to avoid one party being dominant. Mr Salmond declares he has a mandate for a referendum on independence.
September 18, 2014
After desperate efforts by unionists to head off a referendum, one is held. The SNP complains that the 'Better Together' campaign deploys 'Project Fear'. There are threats to stop Scotland using the pound after independence, cut it adrift from the Bank of England, and warnings that it will not be able to stay in the EU. Both Mr Salmond and Nicola Sturgeon say that the referendum will settle the issue 'for a generation'. The unionists emerge victorious by 55 per cent to 45 per cent. David Cameron later indiscreetly reveals that the Queen 'purred down the phone' at him when informed of the result.
June 23, 2016
The UK votes to leave the EU in a referendum, but Scotland votes strongly to retain ties with the bloc. The SNP seizes on the Brexit vote to renew their push, saying circumstance have dramatically changed.
January 31, 2020
After years of bitter wrangling with Brussels and in Westminster, and Boris Johnson winning an 80 majority at a pre-Christmas election, the UK finally leaves the EU. Nicola Sturgeon steps up her calls for an independence referendum vote to be held this year.
As the world is hammered by the coronavirus, Ms Sturgeon declares that she is putting her independence drive on hold. The devolution settlement granted Scotland control of public health issues, and that power has been boosted by new pandemic emergency laws rushed through Westminster. But critics accuse Ms Sturgeon of exploiting the crisis by refusing to move in step with the UK government. She complains that Westminster is denying her funding, even though Scotland has received more than £7.5billion extra, on top of access to national schemes like furlough.
A poll puts support for independence at a new record high of 58 per cent, the latest in a series of surveys to show a surge in separatism.
The SNP says it wants to hold a referendum next year if - as polls suggest will happen - it wins a majority at Holyrood elections in May. Mr Johnson insists he will not allow a new referendum, but there are fears that resisting will merely fuel separatist sentiment.
Mr Brown called on the Prime Minister to set up a commission on democracy which would review how the UK is governed
He writes: 'The commission will discover that the United Kingdom urgently needs a forum of the nations and regions that brings them and BorisJohnson together on a regular basis.
'No country can have national integration without political inclusion, and the commission might start by learning from the experience of countries like Australia, Canada, Germany and America where, partly because of British influence in times past, second chambers are senates of their regions, and minorities who can easily be outvoted are guaranteed a stronger voice.'
A Cabinet spokesman said the public in Scotland want to see the UK's politicians 'working in partnership to focus on defeating coronavirus'.
'That remains the top priority of the UK Government, which has supported jobs and businesses across all four nations throughout the pandemic,' he added.
'The question of Scottish independence was settled decisively in 2014, when Scotland voted to remain part of the UK.
'Now more than ever, we should be pulling together to strengthen our United Kingdom, instead of trying to separate it'.
The Sunday Times poll found that in Northern Ireland, 47 per cent still want to remain in the UK, with 42 per cent in favour of a United Ireland and a significant proportion – 11 per cent – undecided.
However, asked if they supported a referendum on a United Ireland within the next five years, 51 per cent said yes compared with 44 per cent who were against.
In Wales, where support for independence is traditionally weakest, 23 per cent still backed leaving the UK while 31 per cent supported a referendum.
Boris Johnson today slapped down Ms Sturgeon's demands for a new Scottish independence referendum today, saying she should be totally focused on fighting the coronavirus pandemic.
The Prime Minister lashed out at Scotland's First Minister after her Scottish National Party threatened to unilaterally call a new referendum on splitting up the United Kingdom.
Ms Sturgeon used an interview yesterday to claim Mr Johnson 'fears the verdict and the will of the Scottish people' and, ahead of Burns Night tonight, quoted one of his works to accuse the PM of being a 'wee, sleekit, cowrin, tim'rous beastie'.
On a visit to a vaccination centre in north London today, Mr Johnson sidestepped a question about whether he would legally challenge Scottish First Minister Nicola Sturgeon's plans for an advisory independence referendum if the SNP wins a majority in May's Holyrood elections.
'The whole UK is going through a pandemic, I think what the people of the UK want to see is everybody focusing on beating that pandemic, which we are, rolling out the vaccine, and getting ready to bounce back from that pandemic and have the strongest possible economic recovery,' he said.
'I think people also can see everywhere in the UK the visible benefits of our wonderful union.
'A vaccine programme that is being rolled out by a National Health Service, a vaccine that was developed in labs in Oxford and is being administered by the British Army, so I think the strengths and advantages of the Union speak for themselves.'
Taking the Scottish Government to court over the holding of another independence referendum would not be a 'good look' for the UK Government, a senior Scottish minister said.
Mike Russell, Scotland's Constitution Secretary and SNP president, told the BBC he hopes a court battle will not be necessary, adding: 'We're saying to the world: if the people of Scotland vote for something, they should get it - that's unremarkable.
'I think it's such a bad look for any government to say 'Even if the people of Scotland vote for something, we'll take them to court to stop them'.
'(It's) not just the Government - that would essentially be taking the whole people of Scotland who voted for it to court.'
He also said he did not think the UK Government would take such action.
'I think sense prevails, but it is quite fair that we say we intend to deliver that, so we'll carry on with our referendum and if the UK Government wish to challenge that in court, they will have to challenge it and we will defend it,' he said.
Mr Russell would not be drawn on what would happen if the UK Supreme Court rejected the referendum as unlawful.
There is no set timetable for the holding of a referendum laid out in the document, but it does say it must occur after the pandemic has ended.
Independence after the pandemic, Mr Russell said, would allow Scotland to better rebuild after the economic toll taken by Covid-19.
'The connection with the pandemic is to make sure that Scotland rebuilds in the way it needs to rebuild for its future,' he said.
'That is what we need to do, focused on Scotland's needs and Scotland's priorities, not be treated in the way we have been treated over the last many years and particularly during Brexit - that is ignored.'
Nicola Sturgeon (pictured) is unveiling an 11-point roadmap to independence, including a Catalonia-style wildcat vote that would effectively force a drastic response from the Prime Minister to stop it and save the UK
A graphic shows how experts forecast a landslide victory for the SNP in May's Scottish elections