On-the-spot litter fines of €150 will kick in from Saturday
Friday is the final day referendum posters can stay up, before the groups associated with them could be fined.
From Saturday, the Yes and No posters in relation to the Eighth Amendment referendum will be considered litter.
Any posters still up are subject to an on-the-spot litter fine of €150.
Under Section 19 of the Litter Pollution Act 1997 and the Electoral (Amendment) Act 2009, the posters must be removed seven days after polling day.
It is the responsibility of each local authority to enforce the litter law.
It comes amid calls for postering restrictions to be brought in for all future referendum and election campaigns.
The Green Party spokesperson for local government, Councillor Malcolm Noonan, has suggested that the referendum exit polls showed the poster campaign had little influence on voter attitudes or decision making.
"It is clear now that social media is the campaign tool of choice for elections and referenda.
"Posters are environmentally destructive, visually ugly and a waste of money; in the case of general elections, taxpayers money.
"We are proposing that election and referendum posters be restricted by local authorities to designated sites in large towns or cities, where all campaigners and candidates can display their posters.
"This would reduce significantly the number of posters being printed and displayed, improve road safety and the attractiveness of our towns during the tourist season.
"Perhaps over time we could eliminate them altogether, but for now the minister could issue direction to Local Authorities to introduce restrictions."
Last Friday, 66.4% of the electorate voted to repeal the Eighth Amendment.
Some 33.6% voted against the proposal - with a national turnout of 64.1%.