Express.co.uk understands Ireland is drawing up the plans, as well as the possibility of new trade barriers. Leo Varadkar said: "The EU would have no option other than to introduce what we call rebalancing measures.

       Lisa O'Carroll, the Guardian's Brexit correspondent, added: "Varadkar has just told RTE that "Brexit is kind of done but this [art16] potentially undoes it". Had a meeting yesterday on contingency preparations."

       The Fine Gael leader reportedly added: "I don't think anybody wants to see the EU suspending the TCA with Britain.

       "But if Britain were to act in such a way that it was resigning from the protocol resigning from the W/A.. the EU would have no option other than to introduce what we call rebalancing measures to respond."

       Mr Varadkar became a familiar figure in the years following the 2016 referendum, and was involved in several high-profile meetings with both Boris Johnson and predecessor Theresa May over the course of the next few years.

       He stood down as Ireland's leader last year as part of a coalition deal which saw him replaced by Micheal Martin, leader of the rival Fianna Fail party.

       However, as things stand, he is likely to return to the top job in 2022.

       Speaking on Tuesday, Mr Martin said insisted it was not inevitable that the UK Government would trigger Article 16 of the Northern Ireland Protocol.

       The Taoiseach urged Britain to consider the damage such a move would cause to its relationships with the EU and Ireland.

       (More to follow)