Image caption Dr Dominic Bryan from Queen's University, Belfast, carried out a major study examining the flying of flags in Northern Ireland

A police decision to clamp down on flags in a mixed area of Belfast is the "most significant" flag policy move in years, an academic expert has said.

On Thursday, the BBC revealed police are to treat the erection of loyalist flags in the Ballynafeigh area of the Ormeau Road as a breach of the peace.

It followed a meeting between the police and Sinn Féin's Alex Maskey.

The flag expert, Dr Dominic Bryan, said although the move was a "significant shift" it would be hard to enforce.

Years gone by, certainly people using [Irish]tricolours have been prosecuted in the past, but the idea, the possibility that the use of a union flag in various public spaces will be treated as a breach of the peace, is a significant shift Dr Dominic Bryan, Queen's University, Belfast

The police met Mr Maskey after Sinn Féin MLA complained that PSNI officers in his constituency had "brought themselves into disrepute" by watching flags being put up in the Ballynafeigh area.

In a statement to BBC Northern Ireland's politics programme The View, a police spokesperson said tensions were "particularly heightened" by the number of flags being erected in the area.

"As a result, police have directed that any future erection of flags on this part of the Ormeau Road will be treated as a breach of the peace," they added.

The Democratic Unionist Party (DUP) said the move was a mistake and would be "impossible" to police. The Progressive Unionist Party (PUP) has also opposed the move and has asked to meet police to clarify the issue.

However, the Social Democratic and Labour Party (SDLP) has said flags should not be used to "cause aggravation" and called for the new policy to be extended across Northern Ireland.

'Public spaces'

Dr Bryan, from Queen's University, Belfast, has conducted a major four-year academic project examining "the popular flying of flags in Northern Ireland" and has advised the Office of the First Minister and Deputy First Minister on the issue.

He told BBC's Good Morning Ulster programme that it would be "very difficult" for the PSNI to enforce the new south Belfast policy in a "widespread way".

"These things have to go to court and I'd say there would be a question mark as to what the case would look like going to court. However, it does show how things have moved on.

"Years gone by, certainly people using [Irish] tricolours have been prosecuted in the past, but the idea, the possibility that the use of a union flag in various public spaces will be treated as a breach of the peace, is a significant shift," Dr Bryan added.

The four-year QUB flag study was commissioned by the Office of the First Minister and Deputy First Minister, in part to evaluate the government's 2005 flag policy, the Joint Protocol in Relation to Flags Flown in Public Areas.

The academic said: "I would suspect this is the most significant move probably since the protocol was first written in 2005."

"To be honest with you, there has been a bit of a stasis over that period of time around enforcement".

Image caption Ballynafeigh used to be a unionist stronghold in south Belfast but the latest census data has shown that 57% of the people who live there now are Catholics, while 27% are Protestant

He added: "In principle, this has always been possible, but to actually say that this would be a breach of the peace is a significant move."

'No change in policy'

A PSNI spokesman said their policy for dealing with flags had not changed.

He said: "The experience within policing shows that the approach most likely to provide for public safety and prevention of disorder is based on the principles of engagement between local communities, working with agencies including local police, and resulting in local decision-making.

"The removal of flags is not the responsibility of the PSNI and police can only act to remove flags where there are substantial risks to public safety.

He added: "This is entirely in line with existing PSNI policy and practice and does not represent any change in that policy.

"We accept that this can lead to the perception of differing approaches in different areas, but this is the essence of local community resolutions in the absence of a wider consensus."

The DUP MP for East Londonderry, Gregory Campbell, said Irish tricolour flags have been erected in other mixed areas across Northern Ireland and claimed the latest move seemed to be "solely focused on getting the union flag down".

Mr Campbell said tricolours were flying in mixed areas of his own constituency, including the Heights, Coleraine and the Glens estate in Limavady. He added he believed tricolours were erected near the former Erne Hospital in Enniskillen.

He said police were going to face problems in many other areas and described it as an "unworkable solution".

"They are going to be inundated now with people saying 'right, here is a mixed area with flags flying here, we want the same policy implemented here'. Those areas will number dozens of places," Mr Campbell said.

PUP leader Billy Hutchinson said: "The message to the police is you need to police this society fairly. I want to know that you're not having a two-tier system - one for loyalists and one for republicans."

Media playback is unsupported on your device Media caption Sinn Féin's Alex Maskey said officers who watched flags being put up "brought themselves into disrepute."

But Mr Maskey said the erection of flags in his constituency was "bad for the local economy and very bad for local community relations".

SDLP leader Dr Alasdair McDonnell said: "People should not be allowed to cause aggravation, to cause disturbance and to use the flag, whether the British national flag or otherwise, as a tribal element and an element of provocation."

Ballynafeigh used to be a unionist stronghold in south Belfast but the latest census data has shown that 57% of the people who live there now are Catholics, while 27% are Protestant.

In the same census, 36% of the population in Ballynafeigh described themselves as Irish, 32% said they were British, and 29% described themselves as Northern Irish.