Northern Ireland Regional Development Minister Conor Murphy has faced new demands to quit following the Christmas and New Year water crisis.
With Laurence MacKenzie, the chief executive of the water company at the centre of the fiasco, expected to step down, pressure has mounted on Mr Murphy to go as well.
A meeting of the Northern Ireland Water (NIW) board in Belfast is expected to discuss Mr MacKenzie's future as a £250,000-a-year boss following public outrage over his handling of the emergency which left up to 60,000 homes without water at various periods over the holiday.
Nationalists and unionists have called for the resignation of Sinn Fein minister Mr Murphy. SDLP Assembly member Conall McDevitt said: "Many will question now how long minister Murphy's position, that he is the only one who is blameless in the long line of disasters to hit his department and its agencies, is really sustainable."
A spokesman for NIW said Mr MacKenzie, who has held the post since 2009, had "not tendered his resignation". Environment Minister Edwin Poots said it was right that he should be considering his position but added that others in the organisation should also take the blame.
Tens of thousands of homes and businesses were left without water when Arctic weather around Christmas was followed by a swift thaw that ruptured pipes. But NIW failed to cope with the public outcry for information and is accused of bungling efforts to help stricken families.
Ahead of Mr MacKenzie's impending resignation, Mr McDevitt said the chief executive should first give a full account of the crisis to the Stormont Regional Development Committee he is expected to address on Thursday. Committee member Mr McDevitt said Mr MacKenzie had a duty to be accountable. Mr Murphy has promised an independent inquiry into NIW's performance, which First Minister Peter Robinson branded "shambolic".
Meanwhile, NIW said it had re-connected all the homes that had lost water during the crisis. The company said on Wednesday: "NI Water can confirm that we have no properties without supply today. In the east of the province 10 properties have intermittent supply due to low pressure on high ground, and in the west 23 properties are similarly affected. NI Water can also confirm that there are no further planned rotational outages across the province.
"NI Water would reiterate its appeal to customers to check their premises for any damage to pipes and repair these as soon as possible as there remains a problem with leakage on the customer side. This is continuing to contribute to a high level of demand on supply."
It added: "With temperatures forecast to drop again towards the weekend, NI Water wishes to remind customers of the importance to conserve water and insulate water tanks and pipes in unheated areas like lofts, roof spaces, garages and outbuildings."