The EU special envoy to the Colombian peace process, Eamon Gilmore, has said he remains optimistic about its success despite the surprising referendum result.

The former tánaiste and Labour leader said the rejection of the peace deal, by 50.2 per cent of voters, should be seen as part of a process and not an end in itself.

"The experience of our own peace process in Ireland underlines that,'' he added. "It did not stop with the Good Friday Agreement.''

The deal was signed last week by president Juan Manuel Santos and Farc leader Timoleon Jimenez after nearly four years of negotiations. The more than half-century of armed conflict has left an estimated 200,000 people dead.

Speaking to The Irish Times from Colombia, Mr Gilmore said an opinion poll a week before the vote had predicted the Yes side would win by two to one.

“I am sceptical about opinion polls, and I thought it would be carried by a smaller margin,’’ he said. “I spoke to a number of journalists to get an objective opinion, and they believed it the margin would be closer than the polls suggested.’’

Mr Gilmore said the result had to be respected and the work had to continue to bring about a permanent peace. “This is a long-running conflict and I have no doubt that the majority of those who voted want a lasting peace,’’ he said.

Mr Gilmore welcomed Mr Santos’s announcement that he would convene a meeting of political leaders on the issue.

“The detail of the agreement has to be looked now,’’ he said. “As far as the EU is concerned, we have supported the process and will stay with it.’’

Mr Gilmore said it was a question of bringing the various strands of the process together, with the aim of building a lasting peace.