Boris Johnson
Foreign Secretary Boris Johnson leaves after a cabinet meeting ahead of the Chancellor's annual budget at 10 Downing Street on November 22, 2017 Jack Taylor/Getty Images

Government officials in Ireland have been told to 'ignore' Boris Johnson as tensions over the Irish border intensify.

Sky News reported that foreign office officials in Whitehall have told the Irish government "not to listen to whatever he had to say", following a visit Johnson made to Ireland a few weeks ago.

Whitehall told their counterparts in Dublin to pay no heed to the "pubic utterances" that Johnson made.

Ireland has said that it will veto, with the backing of the other 26 members of the EU, opening post-Brexit trade talks if the future of the Irish border isn't decided first.

Johnson, during his trip to Dublin, disagreed with his Irish counterpart, Simon Coveney, over when the future of the border should be discussed.

Johnson claimed that he was unaware of Ireland's call for a transition period lasting four to five years.

As it stands, there is no hard border between Northern and the Republic of Ireland, and this has not been an issue while both are in the EU.

But when Britain exits the EU, the two countries will be faced with a dilemma.

As it stand there is a frictionless border as both nations are part of the customs union and the single market, but this will cease to be the case in March 2019.

The Westminster government's decision to leave both unions mean that new agreements need to be reached over the future of the Irish border.

The EU have made it clear that a border of some kind will need to be imposed because of legal checks needed.

Chief EU negotiator Michel Barnier said: "customs controls are part of EU border management. They protect the single market. They protect our food safety and our standards."

If the UK opts for a very hard Brexit, which would result in the country defaulting onto WTO trade rules, the EU would then impose a series of border checks.

To emphasise that the EU is in control of its borders, they may impose strict rules on border checks. However, in an effort to minimise border backlog, the UK government could opt to carry on as normal and not check the goods that come from Ireland.

The DUP, who are in a confidence and supply deal with the Conservative Westminster government, have warned that they could walk away from any agreements if Northern Ireland remains part of the single market or customs union.