The committee stage debate on the Water Services Bill in the Seanad is expected to continue into the early hours.
Senators have been accused of filibustering as it took over five hours to debate the first tabled amendment before it was withdrawn by Independent Senator Sean Barrett.
It is expected that the Seanad will conclude its committee stage debate tonight and adjourn until Monday when the report and final stages will be dealt with.
Speaking on the first amendment the Minister for the Environment, Alan Kelly, said that he would not support it even though it was put down for the right reason.
"And I accept all of the amendments, even the ones ruled out of order, were put down in the right spirit."
The Minister said that he will accept amendments if they improved or enhanced the bill, but he said he would not do so for the sake of it.
Earlier, independent senator David Norris has "cried shame" on the independent senators or "Endapendents" who voted in favour of the second stage.
He said the Seanad let itself down badly when the "Endapendents", a reference to the Taoiseach's nominees, supported the bill.
Mr Norris was speaking during the order of business this morning ahead of the committee stage debate on the bill.
He said: "I feel that the house let itself down badly last night. This house was saved in order to represent the voice of the Irish people.
"I recognise the Government legitimately used the whip on this occasion, but I very much regret that the so-called 'Endapendents' chose to vote in the way they did."
Fianna Fáil's Thomas Byrne also expressed his disappointment during the order of business.
"There's huge disappointment with the Seanad. We are all being blamed for the actions of a few," he said.
Amendments will tabled in the debate today and several are expected to focus on the future ownership of Irish Water.
Minister for the Environment Alan Kelly has amended the bill and changed the wording to state that there shall be a plebiscite if there are plans to privatise Irish Water.
But many senators want the Government to go further and to hold a referendum on the issue.
The minister said that from a practical point of view he could not guarantee that there would not be unintended consequences if the Government went down the line of a referendum.
Leader of the Seanad Maurice Cummins said the debate will not be guillotined and it will last as long as it takes.
The report and final stages will be dealt with on Monday.
The Dáil is due to sit for two hours on Tuesday if there are any amendments to the bill in the Seanad.
Elsewhere, European Commission President Jean Claude Juncker has articulated his opposition to the privatisation of water and the undermining of public services.
Speaking at the end of the EU leaders' summit, Mr Juncker said: "Public services will not be sidelined, and it is very important that everyone realises that, in the same way that water will not be privatised."
He made the comments in the context of discussing EU-US trade talks, which aim to eliminate certain tariffs and regulatory barriers between the two.
