No10 has confirmed that Rishi Sunak has never paid a tax penalty after facing pressure in the backlash over Nadhim Zahawi.
Earlier today the Prime Minister's press secretary repeatedly refused to answer the question, saying that an individual's tax arrangements "confidential".
No10 was also unable to say whether Mr Sunak is confident no more damaging surprises will emerge about Mr Zahawi's tax affairs.
But in a brief statement this evening, Downing Street clarified: “The Prime Minister has never paid a penalty to HMRC.”
Keir Starmer branded Mr Sunak "hopelessly weak" for failing to sack his party chairman over the row, which erupted when Mr Zahawi admitted he had resolved a multimillion pound tax dispute with HMRC while he was Chancellor last summer.
The Tory chairman said a "careless but not deliberate" error had been made, relating to shares in YouGov, the polling company he co-founded before he became an MP.
In a statement at the weekend, Mr Zahawi also confirmed he had agreed to a settlement, which is estimated to be worth around £5million, including a penalty.
Mr Sunak initially stood by him but on Monday he ordered his ethics chief to launch a probe in a desperate bid to stamp out the growing scandal.
He is now facing questions over his failure to sack the Tory minister.
This afternoon Downing Street was repeatedly asked if Mr Sunak had ever paid a penalty to HMRC like Mr Zahawi but failed to answer.
The PM's press secretary said: "You wouldn't expect me to get into the Prime Minister's tax affairs, they are confidential.
"The tax affairs of an individual, irrespective of who they are, are confidential."
Mr Sunak will publish his tax return "in due course" but the press secretary would not commit to the publishing of six years of the PM's tax returns, as David Cameron did.
Asked by the Mirror if Mr Sunak should answer the question, a Labour spokesperson said: "Yes."
The spokesperson said he would find out if Keir Starmer had paid a penalty and make that public.
It comes as Tory MP Nigel Mills said Mr Zahawi's position "won't be tenable" unless he can explain the penalty.
He told BBC Radio 4’s World at One: “I think the only way to resolve this is to make clear what the situation was that gave rise to a significant penalty and if that can be explained innocently we’ll move on and if it can’t then his position won’t be tenable”.
Asked about whether the matter should be resolved in public, he said: “I can’t see how he can do his job of party chairman when the key thing is to go on the media and defend the government and explain the government’s position which he can’t do at the moment… It’s in his interest to come out and make a complete statement and then we can make a decision one way or another."
