Rishi Sunak was grilled over his knowledge of his Nadhim Zahawi's tax affairs and the bullying allegations against his Deputy Prime Minister at PMQs on Wednesday.
Sir Keir Starmer said Mr Sunak “raised more questions than answers” when he announced Mr Zahawi had been sacked as Tory party chairman at the weekend for breaking the ministerial code.
The former Chancellor failed to disclose that HMRC was investigating his tax affairs, resulting in him paying some £5million including a penalty.
Opening Prime Minister’s Questions, Labour leader Sir Keir said: “When the Prime Minister briefly emerged form his hibernation at the weekend he raised more questions than answers.
“So in the interest of integrity and accountability, can he set the record straight?
“Did his now former chair tell Government officials that he was under investigation by the taxman before or after the Prime Minister appointed him?”
Mr Sunak appointed an independent adviser to investigate Mr Zahawi and said when he set out his findings he "took action".
But Sir Keir responded: "Oh come on. Anyone picking up a newspaper in July last year would have known that HMRC and the National Crime Agency were investigating months before he appointed him [chairman of the Tory party]."
Mr Sunak replied: "As I have said before at the despatch box, the usual appointments process was followed with respect to the minister.
"No issues were raised with me at the time of his appointment, but as the independent adviser's report makes clear, there was a serious breach of the ministerial code and that is why I took decisive action on receipt of that report."
He added: "I take action when these things happen".
The Labour leader also pressed the Prime Minister on bullying allegations against Dominic Raab.
Mr Raab, who is also the Justice Secretary, is facing multiple complaints from civil servants who have worked with him across a range of government departments.
Several civil servants are believed to have given evidence to the inquiry into his behaviour.
Sir Keir Starmer told the Commons: "So in relation to [Mr Zahawi], his defence is: nobody told me, I didn't know, I didn't ask any questions.
“Is the Prime Minister now also going to claim that he's the only person completely unaware of serious allegations of bullying against the Deputy Prime Minister before he appointed him?"
Mr Sunak replied: "The honourable gentleman ask these questions about what was known and I followed due process, I appointed an independent adviser as soon as I was made aware of new information."
Raising the case of Labour MP for Canterbury Rosie Duffield, who has accused her party of sexism after he spoke out on trans issues, the PM added: "But if he is so concerned about what people are saying and so concerned about behaviour in public life, then recently one of his own MPs was forced to speak out because being in his party had reminded her of being in an abusive relationship.
"And then his own office was caught undermining her.
"He ought to be supporting her and her colleagues, but if he can't be trusted to stand up for the women in his party, he can't be trusted to stand up for Britain."
