A new opinion poll to be published tomorrow shows an increase in support for the Lisbon Treaty.

The Red C poll for The Sunday Business Post reveals a shift back to the Yes side in past two weeks.

Tomorrow's poll, based on a nationwide sample of 1,000 voters indicates that supporters of the Lisbon Treaty have gained some ground at the expense of its opponents.

The poll shows support for the Yes side is at 38%, up 3%. 

Support for the No side is at 28%, down 3%, and 34% remain undecided.

Two weeks ago the Yes lead was just 4%, but tomorrow’s poll puts it at 10%.

If the undecided voters are excluded, support for the Treaty leads by 58% to 42%.

The shift to the Yes side appears to due to greater support among Fine Gael members and the farming community.

All parties are gearing up to intensify their campaigns over the coming weeks.