ANY kind of extended devolution of powers across the UK following a No vote could bring down Northern Ireland's power-sharing administration, it has been claimed.

The Stormont Assembly's former finance minister has warned handing further authority to Northern Ireland would be a "disaster", claiming political parties in the fragile coalition are already unable to agree on the limited powers they already have.

In the last fortnight, consultancy and accountancy giant PwC has issued advice to the province's business community on the impact of the Scottish independence referendum, including the potential for a readjustment of the Barnett Formula in the event of a No vote.

Northern Ireland receives more per head of population than any other region of the UK.

The prospect of a significant cut in Northern Ireland's public spending as a result of the referendum has also prompted one leading Belfast Republican to warn of the potential for "social unrest".

Earlier this month Westminster's political leaders promised Scotland more powers after a No vote, particularly around areas of fiscal responsibility and social security.

It has given rise to discussions about a further devolution of powers to the UK's regions, while Prime Minister David Cameron has said recently he will give his decision on the devolution of corporation tax to the North shortly after the referendum.

East Antrim MP Sammy Wilson, who was also the Democratic Unionist Party's finance minister at Stormont for four years, said "concerns over any kind of devo max and demands that will lead in Northern Ireland for more powers to be devolved".

A supporter of the No campaign, the leading Democratic Unionist accused the SNP of "drawing the attention of English MPs to resources going to the periphery".

He said: "On a competency level and the more things we devolve the more difficult it becomes for the coalition to manage them.

"It would be a disaster. We have reached the impasse over welfare reform and built in to our system is the power of veto.

"The more fiscal powers the more costly it will be for Northern Ireland. If there is more devolved to Scotland we are going to get the same. In practical terms given our set-up we can't handle this. Scotland does not have the same coalition set-up."

He added: "By sticking two fingers up at Westminster Alex Salmond is drawing the attention of English MPs to resources going to the periphery. He is doing Northern Ireland a disservice by tweaking their noses."

Dr Esmond Birnie, a former Ulster Unionist Party politician within the Stormont Assembly, is PwC's chief economist in Northern Ireland.

In a recent commissioned article for a local business publication, Dr Birnie spelled out the various implications of both Yes and No votes on September 18 on the region's economy.

He states Westminster could see independence as an opportun­ity to reform the Barnett Formula for the rest of the rest of the UK.

But Dr Birnie adds: "But it may go further. In its May 2010 Programme For Government, the Coalition Government said 'any change to the system (of devolution finding) must wait the stabilisation of the public finances' and that has been accepted as no change to Barnett in the current Parliament.

"This was borne out in Westminster Scottish Questions on December 18, 2013 when Scottish Secretary Alistair Carmichael reiterated there would be no review of Barnett, "in this Parliament," widely taken by Scottish MPs and others to mean that, even in the event of a No vote, a review of Barnett might still be a tempting prospect for Treasury.

"Even a No vote changes the Scottish status-quo."

Prominent Republican Danny Morrison also believes any cut to Northern Ireland's public spending could have a major negative effect.

The former Sinn Fein director of publicity does not believe a Yes or No vote will have any direct impact on the North's population, but added: "Sinn Fein is currently blocking the welfare cuts, which is leading to fines being imposed by the UK Government.

"The Executive has a certain amount of fiscal power but welfare is being hollowed out.

"If there were further cuts following on from devolution of more fiscal powers you would be looking at social unrest. I can't see how much they could cut back. There could be potential impact on the Assembly."

Earlier this week The Herald reported that voters south of the Border want a cut to Scottish annual public spending of almost £1400 per person if there is a No vote.

In 2012/13, public spending per capita in Scotland was £10,327 compared to the UK average of £8,940; meaning a proposed reduction of £1,387.

In the latest signs of crisis at Stormont, Sinn Fein yesterday accused the DUP of implementing "Tory cuts", with the Unionist health minister claiming his department is faced a £140m shortfall due to Sinn Fein.