But Brexit minister Dominic Raab resigned over her deal, sending the pound tumbling. Mutinous lawmakers in her own party openly sought to challenge her leadership and bluntly told her that the Brexit deal would not pass parliament.
Asked if she would contest any challenge to her position, May replied: "Am I going to see this through? Yes." She is due to speak on LBC radio at 0800 GMT.
On Friday, Michael Gove, the most prominent Brexit-supporting minister in her government, gave no comment when asked outside his house whether he would support May. The BBC said May had offered him the job of Brexit minister but he rejected the job.