Latest: Varadkar statement on Brexit 'untimely and unhelpful', says DUP

Latest: The Democratic Unionist Party have hit out at any suggestion of a post-Brexit sea border with the UK.

Update 9.46pm: The Democratic Unionist Party have hit out at any suggestion of a post-Brexit sea border with the UK.

They were responding to comments earlier today from Taoiseach Leo Varadkar, who declared his opposition to creating such a frontier during a robust intervention in Dublin, saying that the onus was on the British government to say how it would work.