A new opinion poll indicates a gain in support for Sinn Féin since the election of Mary Lou McDonald as party leader.

Compared to last month, the main findings in tomorrow's Sunday Times/Behaviour and Attitudes poll sees Fine Gael down four points to 32%.

Fianna Fáil is up two points to 27%, while Sinn Féin saw a rise of three points to 19%.

Independents and others are up one point to 10%, while Labour is also up one point to 6%.

Solidarity/People Before Profit are down two points to 1%  while the Social Democrats are down one point.

This latest poll shows a gap of 5% between Fine Gael and Fianna Fáil compared to the 11 point lead held by the main government party last month.

The drop in Fine Gael support may reflect the controversy over the Government's Strategic Communications Unit and renewed focus on hospital waiting times in emergency departments.

However, the fieldwork for the poll was conducted before the latest controversy following Taoiseach Leo Varadkar's remarks in Washington about his contact with then businessman Donald Trump over a planning issue concerning a proposed wind farm near his golf complex in Doonbeg in Clare.

The poll was conducted by face to face interviews with 900 voters between 6-13 March last and has a margin of error of plus/minus 3.3%.