Sinn Féin Leas Uachtarán Michelle O’Neill has hailed the ‘enormous’ mandates of the SNP and Plaid Cymru as a seismic shift in the political landscape of these islands.

Plaid Cymru made history after overtaking Labour to become the most popular party in Wales last week, while the SNP also emerged as the strongest voice in Scotland.

With Sinn Féin in the north, this now means that the most popular parties in three of the four nations included under the banner of ‘United Kingdom’ now advocate breaking from that union and independence.

Reacting to the election results, Michelle O’Neill said: “For the first time in history there could be three nationalist, pro-independence and pro-self-determination First Ministers,” said Ms O’Neill.

Sinn Féin First Minister Michelle O'Neill has spoken with Rhun ap Iorwerth and John Swinney. (Getty)

placeholder image — Sinn Féin First Minister Michelle O'Neill has spoken with Rhun ap Iorwerth and John Swinney. (Getty)

“I want to send my congratulations to the SNP and Plaid Cymru for their historic success.

"It is clear people want better. They want a brighter future, filled with hope.

“More and more people are looking beyond the constraints of Westminster where decisions are made without regard for people and communities in Scotland, Wales and the north of Ireland.

“That future is beyond Westminster. The desire for independence cannot be ignored.

“I look forward to working closely with John Swinney and Rhun ap Iorwerth to build on the existing relationships, strengthen the ties that bind us and continue the momentum towards constitutional change.”

Sinn Féin leader Mary Lou McDonald also confirmed at the weekend that along with Michelle O’Neill she had spoken to SNP Leader John Swinney and Plaid Cymru’s leader Rhun ap Iorwerth following their historic election results.

"The demand for independence is growing. We look forward to working together in common cause,” she said.

Speaking afterwards, Mr McSwinney posted: “Pleasure to speak this afternoon with the leadership of Plaid Cymru & Sinn Fein. The direction of travel and demand for independence is clear, and Westminster should grasp the significance of this moment.”

Rhun ap Iorwerth meanwhile posted: “It was a pleasure to speak with Michelle O’Neill, Mary Lou McDonald and John Swinney today.

"The potential of Wales, Scotland and Ireland each having First Ministers who believe in the right of their people to self-determination represents a historic moment for these islands.”