Zahawi said Johnson knew “the right thing to do” was to “go now.”
Zahawi was appointed late Tuesday to replace Rishi Sunak, who resigned saying he could no longer support Johnson after a series of ethics scandals.
Education Secretary Michelle Donelan, who was also appointed on Tuesday following the resignation of her predecessor, announced her resignation Thursday morning.

Johnson had rejected clamors for his resignation, digging in his heels even as dozens of officials quit and previously loyal allies urge him to go after yet another scandal engulfed his leadership.
A group of Johnson’s most trusted Cabinet ministers visited him at his office in Downing Street Wednesday, telling him to stand down after losing the trust of his party. But Johnson instead opted to fight for his political career and fired one of the Cabinet officials, Michael Gove, British media reported.
It is rare for a prime minister to cling on to office in the face of this much pressure from his Cabinet colleagues. The Guardian’s frontpage on Thursday called him “Desperate, deluded.”
“He’s breached the trust that was put in him. He needs to recognise that he no longer has the moral authority to lead. And for him, it’s over,” Scottish National Party leader Ian Blackford told The Associated Press.
Last week, Pincher resigned as deputy chief whip after complaints he groped two men at a private club. That triggered a series of reports about past allegations leveled against Pincher – and shifting explanations from the government about what Johnson knew when he tapped him for a senior job enforcing party discipline.
Health Secretary Sajid Javid and Treasury chief Rishi Sunak resigned within minutes of each other Wednesday over the scandal. The two Cabinet heavyweights were responsible for tackling two of the biggest issues facing Britain – the cost-of-living crisis and COVID-19.
Javid captured the mood of many lawmakers when he said Johnson’s actions threaten to undermine the integrity of the Conservative Party and the British government.
“At some point we have to conclude that enough is enough,” he told fellow lawmakers Wednesday. “I believe that point is now.”