Susanna Reid was keen to grill Dominic Raab as he appeared on Tuesday's Good Morning Britain.
The Deputy Prime Minister appeared on the ITV breakfast show to speak to Susanna and her co-host Ed Balls about the findings of the Sue Gray report.
Prime Minister Boris Johnson was branded "unfit for office" after top civil servant Sue Gray said several Downing Street lockdown parties "should not have been allowed".
Susanna, 51, kicked off the interview by asking the Justice Secretary if he felt "ashamed" of the findings.
Skirting around the question, he replied: "I think it's a serious issue and quite rightly been addressed. The Prime Minister has apologised for the failings which ultimately he will take responsibility for.
"He also set out a plan of action to correct them, to strengthen the leadership and the lines of leadership and accountability in No.10.
"He quite rightly wants to wait, and we must all wait, for the police investigation in relation to the 12 specific claims.
"And we're getting on with the business of government, that's what we're focused on."
However, Susanna pressed him: "But can I just ask you a direct question, were the rules complied with during the lockdown?"
"Look, there's serious questions that have been raised about that. Sue Gray, the way that she termed it, is she doesn't think the standards that would be expected had been upheld," he answered.
"I don't think it's right for me to comment on anything that the police are looking at. If I did, I would be criticised roundly for trying to interfere or pre-empt."
Susanna did not back down though and went on to ask him: "With respect, I will just put it one more time: if the Prime Minister is found by the police to have broken the rules, the law as it stood, should he resign?"
"Look, I'm not going to speculate on what they will or will not find...." Mr Raab replied, but Susanna was having none of it.
"I'm not asking you to speculate on what the police find," she fired back.
"I'm saying, let's assume that if the police find that rules were broken... let's put it neutrally, should a Prime Minister resign if they're found to have broken the rules and the law?" Susanna added.
"Again, I don't want to prejudice or pre-empt whatever the police may not only find, but what they decide to do," he answered.
"But what I would say, is of course, it's a very serious set of issues and there'll be proper transparency in relation to all of it and proper accountability, and if those things should come to fruition, they ought to be decided at the time," Mr Raab added.
Good Morning Britain airs weekdays at 6am on ITV and ITV Hub.
