More than 120,000 Irish people between the ages of 18 and 25 may not be registered to vote, according to figures from the National Youth Council of Ireland.

As reported by the Sunday Independent, over 33,000 young people in Dublin are not registered to vote, with 27,000 not registered in Cork and more than 13,700 in Galway.

James Doorley of the NYCI told the Independent, "young people are overwhelmingly in favour of the referendum, but if they are not registered, they can't vote and it could have a big impact on the result so it's very important that they participate." He pointed out that the figures might have dropped since the poll was conducted.

The latest opinion poll - conducted on Monday, Tuesday and Wednesday of this week among 1,006 adults - also assessed those in favour and against the same-sex marriage referendum.

Support levels here compared to a RED C poll six weeks ago, show the Yes at 72, down slightly, No at 20 also down slightly and an increase in don't know's to 8 points.

One in three of likely Yes voters also expressed some reservations in the Sunday Business Post poll, conducted by RED C.

Whether you're in the Yes or the No camp, it's important to remember the deadline to register to vote in both the upcoming Marriage and the Age of Presidential Candidates Referendum is fast approaching.

To check if you are registered, the Referendum Commission’s app can be accessed from its Facebook page here.

It's an easy way for people to check the register and get registered before polling day. Alternatively, people can go straight to checktheregister.ie website (here).

Those who find they are not registered or are registered at the wrong address can correct this if they get the forms to their local authority on or before the deadline of Tuesday, May 5th.

We at Newstalk are urging people to use their vote and have a say in this important referendum and we want the Irish abroad who can't vote to tell us how much it means to them. Find out more details here.