THE leader of the Northern Ireland Green Party will today warn the region is “a powder keg” which could ignite at any moment.

He will also accuse the Tories of putting UK security at risk by committing to a hard Brexit.

READ: The Greenock Agreement in full

In a dramatic intervention Steven Agnew will cite the IRA attack at the Conservative Party conference in Brighton in 1984 to warn of the dangers posed to the whole of the UK by disrupting political stability in Northern Ireland.

Agnew will also be among the Green Party leaders across the British Isles who will today sign a landmark document committing them to join forces to campaign for a swift re-entry into the European Union.

“It is utterly irresponsible of the UK Government to insist on leaving the customs union in the full knowledge that a hard border will be a necessary consequence. The progress of the last 20 years will be put at risk,” he is expected to tell delegates at the Scottish Greens conference today. “The conflict in Ireland dates back over 600 years. It would be naïve to think a relative peace of two decades is secure.

READ MORE: Greens insist they are the party of progressive change in Scotland

“The question is often asked by Brexiteers ‘who is threatening violence’ if there is a hard border. The assumption being that politically everyone is committed to peace. It is an assumption that ignores the reality.

“We have a relative peace it is true. But we still have violent dissident republicans. They may be small in numbers and limited in capabilities but as the IRA warned after the Brighton bomb, the terrorist only has to be lucky once.

“Loyalist gangs continue to terrorise their own communities. While they may have switched to more conventional criminality, the networks remain as does the capacity for violence. I have no doubt that any physical border infrastructure increases the potential for violence and conflict. Northern Ireland is a powder keg and it is a genuine fear that Brexit could be the spark that lights it.”

READ MORE: Nicola Sturgeon and Carwyn Jones write to Lords over Brexit

Jean Lambert, the London MEP, as well as senior figures in the Scottish party will also put their names to the Greenock Agreement.

Eamon Ryan, the leader of the Green Party in the Irish Republic, is to appear via video link at the event and is to sign the agreement later.

The National has exclusively been given the text of the document which underlines the benefits of the EU and states the EU referendum did not give a mandate to leave the single market. It says that the impact of Brexit “will be profound, economically, culturally, politically and environmentally”.

It adds: “Scotland and Northern Ireland did not vote to leave, yet the UK Government continues to deny the devolved administrations, parliament and assemblies any meaningful input in the Brexit negotiations and continues to rule out bespoke deals which better reflect the democratic wishes of the nations or which meet their clearly unique needs. The UK Government’s inability to propose solutions which prevent the return of a hard border on the island of Ireland is a cause of grave concern.”

“We will continue to work in solidarity with our European neighbours ... to commit that if we are indeed taken out of the European Union, we will immediately begin, with the support of our European Green family, the campaign for England, Northern Ireland, Scotland and Wales to re-join.”