Irish Water staff will either lose their jobs or be redeployed if Sinn Fein takes power, Gerry Adams has said.
The party president and Louth TD said the utility would be abolished based on whatever is cheapest for the taxpayer and pensions and redundancies would be worked out on an individual basis.
"The principle is very, very clear - scrap Irish Water, scrap water charges. It's a punitive, unnecessary tax," he said.
Pressed on Sinn Fein's plans to abolish the utility while contracts are in place with four companies, including water metering by the Denis O'Brien-owned Siteserv, Mr Adams said a government led by his party would act on the best legal advice.
"We are lawmakers, if we get a mandate we will change the law to serve the common interest," he said.
"Our objective is very, very clear and this is an absolute red line issue - this and the family home tax - we will scrap both of those."
Mr Adams also said there would be no way to refund people who have already paid Irish Water bills.
The party leader was interviewed on RTE Radio 1's This Week where he was also asked to detail other key manifesto pledges including introducing a living wage for low paid civil and public servants.
He said he did not know if this would have a knock-on effect for wage claims for people at higher levels.
Mr Adams also said he was committed to new laws which would force companies to recognise unions and negotiate with employees based on collective bargaining.
"We stand for the national interest in the common good. We stand by working people. We stand by those people who are disadvantaged and that means we may have to take on these people in the upper echelons," he said.
Mr Adams said his party's plans for a universal healthcare system, free at the point of entry, would take two terms in government to establish.