Three new opinion polls show a commanding lead for the Yes campaign in the same-sex marriage referendum, though the No side is closing the gap.

The surveys for three Sunday newspapers show turnout will be key when the vote takes place next Friday.

The Red C poll for the Sunday Business post surveyed 1009 people nationwide between Monday and Wednesday this week.

Excluding 'don't knows' the Yes side has 73%, with No on 27% - a 10-point tightening in the race since last month.

Millward Brown polled for the Sunday Independent, surveying 994 people at 64 sampling points between May 2nd and yesterday.

This poll had almost a quarter saying they don't know and when excluded it's 69% Yes, 31% No. Since the last comparable poll the Yes side has slipped 13 percentage points, with 10 percentage points of those becoming 'don't knows'.

Image: Millward Brown / Sunday Independent

Behaviour and Attitudes for the Sunday Times interviewed 927 voters between May 1st and 11th.

It shows the Yes side down 10 to 63%; No up 4 to 26; and 'don't knows' up 6 to 11%.

The polls show turnout for each side will be key next Friday - with younger voters more in favour, though historically less likely to vote, while older voters are more against, and tend to turn out.

You can read the results from a separate Irish Times/IPSOS poll here.

Pat Leahy, Political Editor of the Sunday Business Post, outlines their findings:

Originally posted at 18.00