LONDON (AP) — British Prime Minister Rishi Sunak defended his record on integrity and decisiveness Monday, amid criticism of the way he has handled ethics scandals involving senior Conservatives.

Sunak said he acted “pretty decisively” to fire party Chairman Nadhim Zahawi on Sunday after the government’s standards adviser found that he’d breached ministerial conduct rules by failing to come clean about a tax dispute.

The adviser, Laurie Magnus, found that Zahawi hadn’t told the prime minister that he’d settled a multimillion-pound (dollar) unpaid tax bill, and paid a penalty to the tax office, while he was in charge of the U.K. Treasury. Magnus said Zahawi’s failure to tell officials about the tax investigation was “a serious failure to meet the standards set out in the ministerial code.”

“What I have done is follow a process, which is the right process,” Sunak said Monday during a visit to a hospital in northeast England. “When all these questions started coming to light about Nadhim Zahawi, I asked the independent adviser to get to the bottom of it and provide me with the facts.”

He said that on the basis of those facts “I was able to make a very quick decision that it was no longer appropriate for Nadhim Zahawi to continue in government.”

Sunak took office just over three months ago, vowing to restore order and probity to government after three years of turmoil under predecessors Boris Johnson — brought down by ethics scandals — and Liz Truss, who quit within weeks after her policies rocked the U.K. economy.

But critics ask why he did not ask more questions about Zahawi’s tax affairs before appointing him to the key job of party chairman in October, and allege that the government is riddled with bad behavior.

Sunak lost one Cabinet minister, Gavin Williamson, in November over bullying claims, and an investigation is under way into allegations that Deputy Prime Minister Dominic Raab bullied staff. There is also a separate inquiry into ex-leader Johnson, over claims he secured a loan with the help of a Conservative donor who was later appointed chairman of the BBC by the government.

Labour Party chairwoman Anneliese Dodds said Sunak “needed a backbone” and should have sacked Zahawi sooner.

“Why do we see our prime minister continuing to prop up such a rogues’ gallery of ministers?” she said,

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