A new opinion poll has found increased support for the Lisbon Treaty, with more than half signalling they will vote Yes in the second referendum vote.

The Millward Brown Lansdowne survey shows the Yes side up six points to 53% since the last similar survey two months ago.

The No side also went up but by a smaller margin - it now stands at 26%, while the undecided account for 21%.

Excluding the Don't Knows, two out of three of the 1.000 people surveyed, support Lisbon.

Earlier, Independent TD Finian McGrath has confirmed he is backing a Yes vote in the Lisbon referendum.

The Dublin North Central Deputy, who campaigned against the measure last year, said he had taken the decision in the national interest after consulting with his support team.

The referendum will take place on 2 October.

Visit RTÉ.ie/lisbon for more