TORY minister Nadhim Zahawi agreed to pay a penalty as well as settle a multi-million pound tax bill with the HMRC, reports say.

Zahawi, who also serves as the Conservative Party chair and attends Cabinet, paid an estimated £5 million to the tax man after his finances were probed, according to the Guardian.

As part of the settlement, the Tory MP also agreed to pay a penalty, something imposed by the HMRC if the correct tax is not paid at the correct time.

A spokesperson for Zahawi has repeatedly refused to deny that there was a multi-million pound settlement or that a penalty had been imposed.

The settlement was reportedly made in December, which means Zahawi may have had outstanding tax issues while he was serving as Chancellor of the Exchequer.

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The £5m settlement is said to be linked to a failure to pay capital gains tax after the sale of shares in YouGov, the polling firm which he co-founded.

The Guardian reported that some £3.7m had been due in tax after the sale, with a 30% penalty imposed by HMRC as well as interest charges.

Zahawi is believed to be one of the richest men in Westminster, with an estimated net worth of £100m.

The news has led Labour to call for Rishi Sunak to step in and fire Zahawi from government.

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Deputy leader Angela Rayner (above) said: "Rishi Sunak promised a Government of integrity, professionalism, and accountability but instead he's propping up a motley crew of scandal-ridden ministers.

"Nadhim Zahawi's story doesn't add up. The position of the man who was until recently in charge of the UK's tax system and who this Prime Minister appointed Conservative Party Chair is now untenable.

"It's time for Rishi Sunak to put his money where his mouth is and dismiss Nadhim Zahawi from his Cabinet."

A spokesman for Zahawi has said his taxes are “properly declared” and he “has never had to instruct any lawyers to deal with HMRC on his behalf”.

“As he has previously stated, Mr Zahawi’s taxes are properly declared and paid in the UK,” the spokesman said.

The Prime Minister this week said Zahawi “has already addressed this matter in full and there’s nothing more that I can add”.

But Rayner said: “However much the Prime Minister claims the man he appointed Conservative Party Chair has already addressed this matter in full, there are serious and urgent questions that must be answered.”

An HMRC spokesperson said: “We cannot comment on identifiable taxpayers.”