Jacob Rees-Mogg has repeated his accusation that Treasury officials are “fiddling the figures” in their Brexit forecasts, even after a cabinet minister was forced to apologise for agreeing with the claim.

Rees-Mogg, who chairs the pro-Brexit European Research Group of Tory MPs, reiterated his claim that the forecasts were rigged and that the department was determined to keep the UK in the customs union.

He also repeated his assertion, made in the House of Commons, that he had heard the head of a pro-EU thinktank saying Treasury officials had created an economic model to show that all options other than remaining in the customs union were bad.



The Brexit minister Steve Baker apologised to MPs on Friday for saying Rees-Mogg’s account of the remarks by Charles Grant, the head of the Centre for European Reform, was “essentially correct”.

An audio recording of the lunch where he had been speaking emerged which contradicted the claims.

Faced with a demand for an apology from Grant, Rees-Mogg remained intransigent. “The only thing I will apologise for is that it’s turned out to be much more serious than I thought,” he told BBC Radio 4’s Today programme.

“Mr Grant said the Treasury is determined to keep us in the customs union. He also said on another occasion that the Treasury is ‘newly emboldened’,” he said.

“He is getting private briefings from the Treasury against government policy. This is very serious. It is not for officials to invent policy. This is saying that they are determining policy, that they have an aim to lead policy against what the politicians may decide.”

Rees-Mogg’s comments came after Theresa May, on the final day of her official visit to China, appeared to leave the door open to some sort of customs agreement with the EU even though ministers have said Britain will leave the existing customs union.

The MP said Conservative Brexiters could not accept such an arrangement because it would stop the UK from striking free trade deals with other countries.



He said that since the decision to call the EU referendum in 2016 – when the then chancellor, George Osborne, campaigned for remain – it was clear that the Treasury’s economic forecasting had become politicised.



“With all forecasts, the assumptions you make at the beginning determine the outcomes that you get,” he said.

“If you look at the forecasts the Treasury made before the referendum, they were a humiliation. They were clearly politically influenced.

“The Office of Budget Responsibility was set up by George Osborne because the Treasury forecasts had been politicised. It was thought that they were unreliable on political grounds.

“With the referendum and with the EU, the Treasury has gone back to making forecasts. It was politically advantageous for them in the past. It is the same for them now.

“So yes, I do think they are fiddling the figures.”

Grant rejected Rees-Mogg’s account of his comments, although he acknowledged that many in the Treasury did regard staying in the customs union as the “less damaging option” for the economy.

“Mr Baker, a very honourable man, has apologised to me and to the House of Commons for saying things that weren’t quite right. I am surprised that Mr Rees-Mogg hasn’t apologised,” he told Today.

“The Treasury cares about economics so it is naturally pushing for the sorts of Brexit that minimise the economic damage.”

A Treasury spokesperson said: “Both Treasury ministers and officials are working hard to deliver the best Brexit deal for Britain. The prime minister and the chancellor have said repeatedly that we will be leaving both the single market and the customs union. Any suggestion to the contrary is simply false.”