Trade Minister Lord Livingston admitted yesterday that claims the US-EU TTIP trade deal will net Britain £10 billion are simply economic “astrology” that no-one can prove.

In a surprisingly candid admission to the business, innovation and skills select committee the peer said he was reminded of famous economist JK Galbraith’s comment that “the only function of economic forecasts is to make astrology look acceptable.”

TTIP’s backers have long boasted that it will grow the EU economy by €100bn (£75bn) as a whole — with a large slice of that landing in Britain.

That figure was drawn from the “least bad of the studies — other studies show more, there are some that show less.

“It could be higher and it could be lower.

“The answer is none of us will know or be able to ever prove it.”

The Tory was making the first of several Commons committee appearances to face a grilling over the agreement.

And he appeared confused about criticism of TTIP from unions and others.

They have warned that a so-called investor-state dispute settlement (ISDS) section of the deal would shut the door to renationalisation of industry and public services and make it near impossible to reverse the ongoing NHS sell-off.

Replying to Labour MP Katy Clark, he claimed: “I don’t know where this comes from.”

TTIP would merely prevent “discrimination” against firms, he added sniffily.

If a government decided to nationalise and paid no compensation then the ISDS clause would come in, he claimed.