Sinn Féin President Mary Lou McDonald has said that she expects a united Ireland referendum to take place within a decade, adding that reunification would make Ireland "richer, not poorer."

The Sinn Fein President Mary McDonald told the German publication Der Spiegel that Irish reunification must be achieved in "an orderly, planned, democratic and peaceful manner."

She also said a united Ireland will cost a fraction of the price of German reunification, stating that she did not believe that the price associated with a united Ireland would be a deterrent. 

"Irish reunification will cost a fraction of that (German reunification)," McDonald told Der Spiegel. 

"We live on a small, little island. Our border is virtually invisible anyhow. If Brexit had a silver lining – and you have to search for it, believe me – it has had the effect of boosting trade between the north and the south and quickening the integration of the Irish economy. I believe reunification will make us richer, not poorer." 

McDonald said a united Ireland would be built on full and equal citizenship for everyone living on the island of Ireland, adding that unionists in Northern Ireland would be welcome in a united Ireland. 

"In the case of our unionist friends, they are now British living in a partitioned Ireland. In the future, they would be British in a united Ireland. We have no right to steal people’s identity." 

She added that there would be "no circumstances" where Sinn Féin would accept the discrimination of unionists in a united Ireland along the lines "Catholics and nationalists suffered in the North."

McDonald also said she believed concrete issues such as healthcare would be more important for people who were voting in a united Ireland referendum than symbolic issues such as flags and anthems. 

However, a US academic has warned that there are no imminent prospects of a unity referendum in Northern Ireland. 

Boston-based professor Padraig O’Malley, who has been immersed in Northern Ireland politics for the past 50 years, described Sinn Féin as the biggest barrier to a united Ireland.

"Sinn Féin is the biggest obstacle to a united Ireland. It is an irony that the party whose raison d’être is a united Ireland is perceived as making that goal more difficult to achieve," O'Malley told the Irish Times.

O'Malley added that the perils of any united Ireland vote will outweigh the benefits.