SCOTLAND should renounce any claims over Rockall and “reject complicity in Britain’s last act of colonialism”, a Scottish Green MSP has said.

Andy Wightman made the comments amid a growing row over fishing rights in the waters around the uninhabited North Atlantic outcrop, located around 300 miles from the Scottish mainland.

The Scottish Government has threatened to take action if Irish vessels continue to operate in the zone around Rockall, which the UK has claimed sovereignty over since 1955.

But speaking in Holyrood, Mr Wightman, who said he is an Irish citizen, insisted Scotland should renounce its claims over the island.

Addressing External Affairs Secretary Fiona Hyslop, he said: “The minister will be aware that Rockall was annexed by the British Crown on the advice of the Colonial Office when in September of 1955, Lieutenant Commander Scott landed on the rock, raised the union flag and announced ‘in the name of Her Majesty, I hereby take possession of this island of Rockall’.

“Does the minister agree with me that we should reject complicity in Britain’s last act of colonialism, make it clear we’ll have nothing to do with such land grabs and instead renounce any Scottish claims over Rockall?”

It came amid reports Irish skippers were preparing for a confrontation with a Scottish patrol ship heading towards Rockall.

Scottish ministers insist they are defending the interests of fisheries against a rise in “illegal activity” around the granite outcrop.

But Ireland’s deputy leader Simon Coveney has refused to back down, insisting it does not accept “that a very small rock constitutes a sovereign territory”.

Ms Hyslop said Scotland’s relationship with Ireland “is strong and we value it highly”, adding: “It has now been agreed that a process of intensified engagement will take place, led by senior officials from both administrations.”

She added: “While that discussion takes place, Marine Scotland will continue to monitor the area using aerial and satellite capabilities.”

She said the Scottish Government became aware of a significant increase in fishing by Irish vessels in 2017.

In response to Mr Wightman, she said Scotland’s obligations and responsibilities are clear in relation to fisheries management.