Dogs wearing a union flag (L) and a Scottish flag attend the 150th Birnam Highland Games in Perthshire, Scotland, on August 30, 2014
London (AFP) - Whether Scotland votes for independence or not, the referendum has fired up debate in the rest of the United Kingdom over London's dominance and the historic ties that hold the country together.
From Northern Ireland to Wales and even within England in regions like Cornwall and Yorkshire, the run-up to the September 18 vote has stoked long-running opposition to control by the capital.
"Even if there is a No vote, we are looking at some important constitutional changes in the United Kingdom," said Graham Walker, professor of politics at Queen's University Belfast.
"I think we'd be looking at a looser union, perhaps a kind of federal union," he said.
All three of Britain's main parties have promised new tax powers for Scotland's Holyrood parliament if the referendum is rejected, as indicated by all the opinion polls so far.
Other parts of the union could say "us too".
First among these would be the Welsh independence party Plaid Cymru, some nationalists in Northern Ireland, and Mebyon Kernow, which campaigns for a governing assembly in Cornwall, where one in seven claim a Cornish national identity.
Polls show support for independence in Wales is far below the roughly four in 10 Scots who want to leave the union. But more than a third of the Welsh want more powers for their assembly.
Promises of more powers for Scotland will likely spur challenges to restrictions on the Welsh assembly's power to set income tax bands, in a bill set to return before parliament in October.
In Northern Ireland, the debate has also given impetus to demands for the power to set corporation tax to compete with the 12.5 percent rate of the Republic of Ireland -- far below the main 21 percent rate set by London.
- Growing regionalism -
The main parties in Westminster have already declared their support to give more powers to cities and regions.
In July both the Labour and Conservative parties made rival promises to give local authorities control over billions of pounds in spending, setting up decentralisation as a key battleground ahead of the May 2015 election.
Prime Minister David Cameron promised to transform a "too London-focused and too centralised" economy, while opposition leader Ed Miliband said his plan would "reverse a century of centralisation".
London, a financial hub whose vast economy outstrips much of the rest of Britain, is widely seen by the public outside the capital as dominating policy-making at the expense of other regions.
"I can understand and sympathise with why people want independence in Scotland," said Lucy Wallace a 28-year-old cultural producer who lives in Sheffield.
"A lot of people feel the government is very out of touch," she said.
This frustration has been linked to the rise of the UK Independence Party, which campaigns to "recover power over our national life" by leaving the European Union.
In its 2014 manifesto the party vowed to "bring back power to the people" by introducing local referendums on planning and service decisions.
The decentralisation fervour is present even within Scotland, and the Scottish National Party has promised that local authorities in the Orkneys, Shetlands and Western Isles will have more power under independence and a greater share in North Sea oil wealth.
- 'Held together by a thread' -
Reaction in Northern Ireland will be split between the nationalist and unionist communities, and risks upsetting a precarious peace already rocked by entrenched disagreement over flags, marches and the legacy of the decades of violence known as The Troubles.
For unionists, who have strong cultural links to Scotland, a vote for independence would be "devastating", according to Walker of Queen's University.
Loyalists fear Scotland leaving would undermine them and fuel nationalist demands for unification with the Republic of Ireland, and plan to march through Edinburgh ahead of the referendum in opposition to independence.
Earlier this year Sinn Fein leader Gerry Adams said "the so-called United Kingdom is held together by a thread" that could be "unravelled by referenda".
The party has previously called for Northern Ireland to hold a referendum on a united Ireland by 2016 -- the centenary of the 1916 rebellion against British rule.
During a heated Scottish referendum debate, the "No" campaign leader Alistair Darling pleaded with his rival Alex Salmond: "We do not need to divide these islands into separate states in order to assert our Scottish identity".
But for Alan Trench, devolution expert and honorary senior research associate at University College London, the decentralisation trend is inevitable.
"There is clearly now an increased debate across all parts of the UK about what the union means and where the locus of power should be," Trench said.
"The UK in 20 years time will look very different from the UK today. And if it doesn't, it will be a very unhappy and very unstable ship."