Joan Burton says she believes people will, eventually, accept the need for water charges.
The Tánaiste was responding after a demonstration on Saturday against water charges, which organisers say was attended by 88,000 people.
Another demonstration is planned next month after the first bills arrive.
Ms Burton says she accepts that many people still object to charges for water on a point of principle.
But she is standing by the government plans - and says that people will accept them in time.
Meanwhile the Environment Minister Alan Kelly says he is happy with the level of compliance with water charges through registration with Irish Water.
Mr Kelly refused to be drawn on the expenditure of €900,000 on consultants for the Commission for Energy Regulation (CER).
But he told Newstalk Lunchtime that employers are concerned over the future of Ireland's water supply.