The Revenue Commissioners are carrying out an examination of the reintroduction of Border controls if the UK votes to leave the EU.

The Irish Times has learned an analysis is under way by the agency of how many Customs officers would be required to staff potential controls between the North and the Republic.

Revenue is also examining the introduction of automated Border controls to be established in the aftermath of a Brexit.

This would mean there would not be a need for the constant presence of an immigration officer, and processes could be carried out electronically.

The Government is also understood to be preparing a contingency plan to outline how it will deal with a “Leave” outcome.

However, it is said to be confident it has a two-year timeframe to address the risks and opportunities that arise from a Brexit.

The Government is said to be aware a "Leave" vote would bring economic, trade, legal and operational risks for Ireland.

A British exit from the EU would have similar consequences for other countries that trade with the UK.

However, it is suggested the impact on Ireland would be proportionately greater than on other member states.

The key areas identified for such impact are trade, markets, migration, social welfare, energy market, foreign direct investment and Northern Ireland.

Fall in trade

Every 1 per cent decrease in UK GDP can normally be expected to result in a decrease of 0.3 per cent in Irish GDP, according to research from the Economic and Social Research Institute.

The Government fears trade between Ireland and the UK could fall by as much as 20 per cent in the medium term.

It anticipates the agrifood business, in particular, would be particularly vulnerable.

There is also concern that there may be disproportionate adverse impacts on jobs here.

Any changes to the common travel areas will have consequences for migration flows between the UK and Ireland.

Border controls may be reintroduced and Revenue is working to examine the repercussions for travel between Northern Ireland and the Republic.

Issues may also arise for foreign direct investment and the possibility that it may be diverted elsewhere in the EU.

Strategies may be implemented and developed to mitigate these effects on the economy.

Implications

The Government’s plan will incorporate details from each Minister, department and agency about the policy, operational and programmatic implications that will follow.

A referendum on whether the UK should stay or leave the EU takes place on June 23rd.

Senior Government Ministers and the Taoiseach are expected to travel in the coming weeks to urge the Irish living in Britain to vote against a Brexit.

It has been estimated by campaign groups there are about half a million first-generation Irish living in England, Scotland and Wales.

A communications strategy has also been be prepared and diplomatic contact has been prepared for the outcome.

It is understood the Government is also preparing plans in the event that the UK remains a member of the EU.

As part of an agreement reached by heads of state and government at an EU Council meeting, four key measures were agreed in the areas of economic governance, competitiveness, sovereignty and social benefits.

If the UK remains, Ireland will examine whether it will avail of its agreement on child benefit payments.

The proposal would see payments brought into line with standard of living in the state of residence.