Claim that UK membership of EU is worth £3,000 to every British family branded 'blatantly misleading'

A claim that Britain’s membership of the EU is worth £3,000 to every UK family has been branded “blatantly misleading” and “a scandalous abuse of data”.

In a bruising session in front of the Commons Treasury Committee, Lord Rose, the chairman of the main “in” campaign, was savaged by the committee’s chairman, Andrew Tyrie, over the group’s continued use of the claim.

Mr Tyrie, who has yet to come out for either side in the referendum debate, urged the former Marks & Spencer executive to remove the claim, telling him that to continue using it would be “intellectually dishonest”.

During the session, Lord Rose appeared unable to answer Mr Tyrie’s questions about when the five studies from which the number was derived were published and whether they related directly to the UK. He was also forced to admit that he had not read all the documents himself.

But he insisted he stood by the figure, which he said was produced by the CBI as a central estimate drawn from the results of the five studies.

Mr Tyrie said that the most recent of the studies was 10 years old and the oldest dated back to 2002, while two of them looked at the EU as a whole, rather than focusing specifically on the UK, and one said the costs of membership outweighed benefits.

He told Lord Rose: “You are leading the campaign with this number; this isn’t some recondite number in a footnote. This is one of the most important components of the case you want to put for continued membership of the EU by the UK.

“Don’t you think it is incumbent on you to make absolutely sure that number is robust? Yet you have come before the committee and you didn’t even know that one of the five studies in question concluded that there were net disbenefits.”

But Lord Rose accused the committee chairman of “impugning [his] integrity”.

He said: “Mr Tyrie, you have made it quite clear that you think the information I have laid out is absolute rubbish and you are obviously entitled to our own opinion. I stand by what I have said.

“You are perfectly entitled to call my credibility into doubt, but what you are effectively saying is that the CBI – which is a much-respected organisation in the UK representing business – is putting out propaganda which is untrue. Frankly, I find that incredible.”

Britain Stronger in Europe chief executive Will Straw stepped in to try to calm the row, saying the CBI had used a “very standard economic practice” of reviewing existing research into the economic impact of EU membership.

“With this statistic and all the others we have used, we have made every effort to make sure we have used the most accurate information,” said Mr Straw.

“We have satisfied ourselves that it is accurate. We will continue to use it.”

Boris Johnson’s brother Jo – who is the Universities Minister and supporting the Remain campaign – will warn on 3 March that science and technology firms could suffer in a “decade of uncertainty” following a British exit.

In a speech at Cambridge University, the minister will acknowledge that the UK could survive outside the EU – but its status as a “science superpower” would be put at risk. “We need to be building academic partnerships with our close neighbours, not turning our backs on them,” he will say.