Irish Prime Minister Enda Kenny has warned that a British exit from the European Union (EU) is a "critical issue" for his country. Kenny met with Prime Minister David Cameron and discussed the potential exit in London on Monday (25 January).

Ireland have been vocal opponents of the potential "Brexit", saying that it could damage trade between the nations, and in particular effect the economic and political relationship with Northern Ireland if it leads to more border controls.

"You know our position in Ireland – Europe would be much stronger with Britain as a central and fundamental member. So it's a vital issue for Europe, its a vital issue for Britain, but it's also a critical issue for Ireland," Kenny said. "We can be a stronger Union, a stronger Britain, a stronger Ireland by making changes that reform Europe in a way that helps everybody," he added.

The potential EU exit will be voted on before the end of 2017. The Prime Minister is campaigning to stay in the EU, but wants to negotiate reforms to Britain's relationship with the continent before the referendum.

Cameron said: "I think we should be focusing on the positive opportunity for Britain. Imagine the scale of the prize if we can remain a member of the single market with 500 million consumers, a quarter of the global economy with a seat at the table and a say over the rules, making sure we do right by our business for jobs, investment and growth in the UK. We can make sure we deal with the things that frustrate people about the EU."

The UK is Ireland's biggest trading partner, with the two countries trading over €1bn (£750m) every week.