Sinn Féin and leader Gerry Adams have suffered a drop in support in newspaper opinion polls, following a week in which the Maíria Cahill controversy was a key issue on the political agenda.

Independents emerged as the winners, as public anger with Irish Water and charges damaged Fine Gael and Labour and Fianna Fáil failed to make a breakthrough.

The Sunday Business Post/Red C monthly tracking poll showed Sinn Féin at 20 per cent, down three points. Fine Gael at 26 per cent was down two points; Labour at 8 per cent showed no change; Fianna Fáil at 18 per cent also showed no change; Independents were up five points to 28 per cent.

Support for Sinn Féin in the Sunday Times Behaviour and Attitudes (B&A) poll remained unchanged at 19 per cent; Fine Gael rose one point to 25 per cent; Labour was down five points to 9 per cent; Fianna Fáil was unchanged on 18 per cent; Independents were up three points to 25 per cent; the Green Party increased by one point to 3 per cent.

Mr Adams's personal rating was down from 47 per cent to 40 per cent, but he was still just one point behind the most popular party leader, Tánaiste and Labour leader Joan Burton who was down four points to 41 per cent.

Mr Adams’s satisfaction rating among Sinn Féin supporters remained very strong, increasing by six points to 89 per cent.

Taoiseach and Fine Gael leader Enda Kenny’s personal rating was down six points to 29 per cent; Fianna Fáil leader Micheál Martin down two points to 37 per cent; Green Party leader Eamon Ryan down four points to 33 per cent.

Voter-anger about water charges was reflected in the Sunday Business Post poll, as 65 per cent said they would pay, while 35 per cent said they would not, excluding those who said they did not know or were not liable.