The UK Business Secretary has described the prospect of Britain leaving the EU as a ''nightmare scenario'' that would throw up a ''green wall'' across the island of Ireland.

Vince Cable said it would make it much more difficult to develop trade between both parts of the island if Britain were no longer in the EU and the single market.

Mr Cable was addressing a conference organised by the British Irish Chamber of Commerce in Dublin's Aviva stadium this afternoon.

But the Business Secretary said he felt it was highly unlikely to happen and he was 'virtually certain' Britain would remain within the EU.

However, he said the Irish experience showed that referenda were not predictable and it needed to be considered.

Mr Cable said he and others would work to reduce uncertainty that had been created in certain areas.

In his speech, Mr Cable also underlined the importance of the trade relationship between Ireland and the UK, commenting that “the relationship between Ireland and UK is massively positive''.

He said that since 2003 there has been £10.5 billion of UK foreign direct investment into Ireland creating over 55,000 jobs. Almost €1 billion of goods and services are traded weekly.

''Ireland is a very important trade partner and this is something we want to build on further,'' he stated.