Taoiseach Enda Kenny has hailed the agreement struck after two days of negotiations in Brussels on Britain's future relationship with the European Union.

Mr Kenny said the unanimous agreement, announced by Donald Tusk, President of the European Council, at around 9.45pm last night, was in Ireland's, Britain's and Europe's interest.

Mr Kenny said that since Ireland had a co-guarantor status of an international agreement in the Good Friday Agreement with the UK, it was "very much in Ireland's interest from many points of view that Britain stay a member [of the EU]".

However, Mr Kenny said that "no Irish worker" living in the UK would be affected by any of the provisions of the deal which restricted in-work benefits or child benefit arrangements.

He accepted that the European Commission would have to examine any exemption enjoyed by Irish workers in Britain that were not enjoyed by the nationals of other member states.

He also said the Government would examine the implications of the deal as they pertained to child benefit rules.

Mr Kenny said there had been a provision for limiting the amount of child benefit that EU nationals working in Ireland could send home in the 2011 Programme for Government.

The hard-fought deal struck among EU leaders in Brussels allows all member states, from 2020, to index child benefit being sent to another EU country to the standard of living in that country.

Officials have calculated that the amount of child benefit sent out of Ireland was in the region of €12m.

Despite two days of fraught negotiations over issues such as welfare benefits, the treaty aspiration of "Ever Closer Union", and the rules governing those inside and outside the eurozone, Mr Kenny said there had been "genuine warmth" among the leaders towards the final agreement.

He described the result as "a win for Europe".

But he added: "It is very clear to me that this is only the start of the campaign. The situation insofar as having the British electorate vote in favour of the UK continuing to be a member of the European Union is only starting and the circumstances, the parameters of that debate, are still the same."

On the effect of the restrictions on EU nationals living in Britain, Mr Kenny said: "No Irish worker in Britain is affected by this. There's a very clear understanding, as you're aware, from the British government and the prime minister, of the common travel area [between Britain and Ireland], of the Schengen Agreement, the fact that the Irish people in Britain will vote in the referendum, that so many participate in the community and business life in Britain, that's a very particular relationship.

"We're happy that Britain fully understands that, and they're happy that they understand it."

Mr Kenny said that arrangements would be made between Ireland and Britain after the referendum to ensure that Irish workers were not affected by any new restrictions.

Asked if he feared that an exemption for Irish workers would breach the EU principle of non-discrimination, Mr Kenny accepted that any new arrangements would have to be agreed to with the consent of the European Commission.

Minister for Foreign Affairs Charlie Flanagan has also welcomed the outcome of the discussions.

Mr Flanagan said the agreement is "a very significant development", adding it marks the culmination of several months of negotiations.

He added that the Government is "strongly of the view that the UK should remain in the Union".