Downing Street confirmed the departure of Brexit negotiator with a statement, topping a torrid week for the British prime minister after a party rebellion on new coronavirus curbs and by-election defeat.

David Frost, UK government trusted ally to leave in January in a
David Frost, UK government trusted ally to leave in January in a "disillusionment" with the Boris Johnson administration. (Reuters)

Britain's Brexit minister David Frost has resigned due to disillusionment with Prime Minister Boris Johnson's government, including the imposition of tax rises and additional Covid-19 restrictions.

"I think it is right for me to write to step doesn't with immediate effect," said Frost in a statement on late Friday.

Frost also noted that the Brexit is "now secure" and Johnson's administration should not be "tempted by coercive measures."

"We need regulated, low tax, entrepreneurial economy," he added.

The resignation news firstly reported of the local daily Mail.

The newspaper said Frost's resignation had been prompted by the introduction of additional Covid-19 measures, including Covid passes, a broader discontent with tax rises and the cost of 'net zero' environmental policies.

If confirmed, the departure of the British government's most senior Brexit negotiator is yet another blow to Johnson, who has faced warnings from some of his own lawmakers that he must improve his leadership or face a challenge.

Johnson said on Friday that he takes personal responsibility for the loss of a Conservative stronghold in an election defeat that showed public dismay over a litany of scandals and stepped up pressure from mutinous lawmakers.

"Lord Frost tendered his resignation a week ago - but was persuaded to stay until January," the newspaper said on Twitter.

Frost, a supporter of Brexit who negotiated Johnson's revised EU divorce deal and a trade agreement, has led the attempts by London to renegotiate the terms of Britain's exit from the European Union.

READ MORE: EU offers several proposals to resolve Northern Ireland Brexit row 

Future of post-Brexit UK

In a speech last month, Frost expressed his clear discontent with the current course of post-Brexit British policy.

"We have not successfully rolled back the frontiers of the European Union from Britain with Brexit, only to import that European model after all this time," Frost said in a Nov. 22 speech at the Margaret Thatcher Conference on Trade.

He disagreed with "those who think we can treat the private sector as just a convenient way of keeping the public sector running".

"It isn't just a source of taxes," Frost said.

"We can't carry on as we were before, and if after Brexit all we do is import the European social model we will not succeed."

After talks with the EU, Frost said on Friday that negotiations were not close to solving problems that the Northern Irish protocol he negotiated had created.

"It is disappointing that it has not been possible to reach either a comprehensive or worthwhile interim agreement this year," Frost said. "A solution needs to be found urgently early next year."

"For as long as there is no agreed solution, we remain ready to use the Article 16 safeguard mechanism if that is the only way to protect the prosperity and stability of Northern Ireland and its people," he said.

READ MORE: UK-EU spat over Northern Ireland trade overshadows G7 summit

Source: TRTWorld and agencies