An age old controversy surrounding the ownership of Rockall - the uninhabited rock 435km off of the Donegal coast - could be reignited as the UK prepares to leave the EU.

Jane Morrice, a former European Commission representative in Northern Ireland told the BBC that she believes that Brexit, "Could raise the age-old controversy over ownership of Rockall which was more or less resolved between the UK and Ireland in 2014."

"The fact that the rock outcrop in the north Atlantic is claimed by the UK as part of Scotland could make it a small but serious point in future negotiations," she added.

Ms Morrice has warned that the UK going outside of the EU's Common Fisheries Policy will renew debate concerning sea borders.

As is, Irish fleets are free to fish in this part of the Atlantic - but this could change.

Fianna Fáil's Éamon Ó Cuív has warned that, "In the event of a hard Brexit, there is a strong desire by many in the UK fishing industry to 'pull up the drawbridge' and push for a ban on non-UK fishing fleets fishing in UK waters so that the currently shared fishing zone will be the UK's and the UK's alone."

Britain's case

The UK landed military personnel on the Rock in the 1950s and has a long laid claim to Rockall, although that claim has never been recognised by the international community.

The British navy attempted to annexe the rock in 1955, hoisting the union flag and cementing a brass plaque on the rock's summit.

The 1972 Island of Rockall Act was passed by the British Parliament and claimed the rock as part of Scotland.

However, the UN convention on the law of the sea rules that "Rocks which cannot sustain human habitation or economic life of their own shall have no exclusive economic zone or continental shelf."

The Irish Government agree to sea boundaries with the UK in 1988 - which put Rockall in British territory - as illustrated on this map from the Department of Foreign Affairs.

Department of Foreign Affairs

"While Ireland has not recognised British sovereignty over Rockall, it has never sought to claim sovereignty for itself. The consistent position of successive Irish Governments has been that Rockall and similar rocks and skerries have no significance for establishing legal claims to mineral rights in the adjacent seabed or to fishing rights in the surrounding seas," the Dail was told in response to a parliamentary question from Catherine Murphy in 2012 over the stance of the rock.

Unsettled

While Ireland has agreed to the above boundary with Britain, it has never been recognised by the United Nations. It has been disputed by both Iceland, and Denmark (as the country is responsible for the foreign relations of the Faroe Islands).

The four countries have met regularly since 2001 in an effort to resolve the issue - but with no success.

The rock is mentioned in both Irish and Scotish folklore - it is said to be a sod of earth pulled from Ulster by the giant Fionn mac Cumhaill and thrown at a rival. The Scotts believed that it was a mythical rock which would appear three times before the world ended.

Last year, the British Government awarded a grant to Aberdeen University collect geological data concerning possible oil and gas reserves around the rock.