The Government is to push for a commitment that Northern Ireland will be given speedy admittance to the European Union in the event of Irish unity.

Sources have said the talks on Britain’s departure from the EU, due to begin by the end of March, must take account of the prospect of a future Border poll.

A referendum on Irish unity is allowed for in the Belfast Agreement but only if certain conditions are met.

The example being cited, and the argument that will be deployed by the Government, is that of East Germany becoming an automatic member of the then European Community on the day of German reunification in October 1990.

One well-placed source said the Government will “look for the same thing in relation to the North”.

“You could be talking in 20 years’ time if the people of Northern Ireland decide to join up,” said a source.

It is stressed, however, that such a move towards Irish unity could only come about under the processes outlined under the Belfast Agreement. It states that the UK secretary of state for Northern Ireland can call a referendum if it appears likely a majority of people in the North want Irish unity.

Membership conditions

Joining the EU can take years, with candidate countries having to satisfy a number of conditions even before formal negotiations officially begin.

Taoiseach Enda Kenny has previously spoken of the German example, saying East Germany was “able to be absorbed into West Germany and not have to go through the long and torturous process of applying for membership of the European Union”.

Government sources want this and other Ireland-specific issues settled early in the Brexit talks process to avoid them being held “hostage” when negotiations come to their tense conclusion.

Ministers and officials were briefed before Christmas about precedents which could set an example for Ireland as Britain departs the EU.

As well as the former East and West Germany, the example of Norway and Sweden, a non-EU member sharing a land border with a member, was also mentioned.

A customs border is in place between Norway and Sweden and, while electronic number-plate recognition is used, there are still some checks by customs officials. Norway, however, has access to the single market through its membership of the European Economic Area and accepts the so-called “four freedoms”: the free movement of goods, people, services and capital. The British government is unlikely to follow the Norwegian model.

Post-Brexit trade

Meanwhile, the Government is to announce a new post-Brexit trade strategy for Ireland in the new year. It will put in place a framework for future Irish trade and draw on existing strategies in areas such as agri-food and innovation. It will aim to push Irish exporters towards new and existing markets in an effort to reduce dependence on Britain.

The strategy will primarily be driven by the Department of Foreign Affairs, which will utilise its embassy network in building up trade, and the Department of Jobs. Organisations such as Bord Bia and Enterprise Ireland will also be involved.

It will also aim to drive certain sectors towards markets that may be receptive to their products and will emphasise prospects in both new and mature markets. This could entail exploiting opportunities in Canada, which has just concluded a free trade deal with the EU, while also increasing trade into large EU markets, such as France.

Sources said the new trade strategy will take on sharper focus because of the likelihood that the proposed US-EU free trade deal will be abandoned by US president-elect Donald Trump.