The Northern Ireland First Minister Arlene Foster has a duty to attend the all-island forum on Brexit, Sinn Féin has insisted.

Ms Foster has declined the invitation to attend the civic forum, which takes place in Dublin on Wednesday.

Sinn Féin deputy leader Mary Lou McDonald said Ms Foster should re-consider her stance.

She said Brexit was the biggest challenge the country has ever faced and all those involved should participate in the discussions.

Ms McDonald said: “I would say to Arlene Foster there is a place for her at the table within this forum and it is within the forum that points of views, arguments and suggestions should be made.

“She should be there, maybe she will reconsider. Maybe the DUP (the Democratic Unionist Party) will reconsider and participate in this.

“I think they have a duty to do so because obviously Arlene is the First Minister but also because they recommended Brexit as their preferred option.”

The forum was proposed by Taoiseach Enda Kenny with no consultation with Ms Foster.

She has insisted the lines of communication between the two governments are always open and therefore the forum is pointless.

Ms Foster said those attending the event will spend the day criticising the outcome of the referendum rather than dealing with the outcome.

Ms McDonald said the forum must not become a talking shop or a platform for negativity.

She said: “We have real and imminent threats to our economic life, to the social life and fabric particularly of border communities.”