Labour vows to force Government to publish secret Brexit reports laying bare economic damage

Ministers face Commons showdown after insisting the document – which concludes three possible Brexit options would leave Britain poorer – will remain secret

Labour has vowed to win a Commons vote to force the release of secret analysis laying bare the economic damage from Brexit.

MPs will vote on Wednesday as angry Conservative MPs joined attacks on ministers for insisting the document – which concludes three possible Brexit options would leave Britain poorer – must remain secret to avoid harming the “national interest”.

The clash threatens to be a repeat of the defeat that ordered the Brexit Department to release 58 “impact assessments” for various economic sectors, although a red-faced David Davis later admitted they did not exist in that form.

Meanwhile, the latest leak led to angry recriminations as the Brexit Department sought to deny it had commissioned the research, only for a senior source at the Cabinet Office to insist it had been done at the Brexit Secretary’s behest.

In the Commons, Steve Baker, a Brexit minister, launched an extraordinary attack on economic forecasting – arguing it was “always wrong” – triggering a protest from the Whitehall trade union, which said it was an “insult” to dedicated professionals and suggested he should be sacked.

Sir Keir Starmer, Labour’s Brexit spokesman, vowed to force the report’s release, telling Mr Baker: “Publish it now – not in nine months, but now, so we can hold the Government properly to account.”

And he warned: “The Secretary of State has a chance today to avoid a repeat of that exercise [on the impact assessments] if he commits to publishing this new analysis in full.”

Mr Baker said MPs would be given “appropriate” analysis when the negotiations are over and before this autumn’s “meaningful vote” – but claimed publishing the incomplete leaked study would “risk exposing our negotiating position”.

Some Conservative MPs also demanded publication. Heidi Allen said: “This is a one-time deal only and I, for one, owe it to my constituents to prove to them that I have exercised full scrutiny.”

Veteran Pro-EU Tory Ken Clarke accused ministers of secrecy because of the “embarrassment”, telling Mr Baker: “Stop pretending that it is something to do with defending our negotiating position.”

And Antoinette Sandbach warned of damage to the car, food and chemical industries, telling Mr Baker: “I take exception to being told that it is not in the national interest to see a report that allows me to best represent my constituents.”

Labour MP Chris Leslie warned it would only be published when ministers had had a chance to “edit it, twist it, distort it, [and] redact the information in it”, adding: “A cover-up pure and simple – and it stinks.”

But Mr Baker called the document a “selective interpretation of preliminary analysis” and condemned its leak as “an attempt to undermine our exit from the European Union”.

Later, he defended keeping the analysis secret, arguing the public did not want to “engage in the details of trade policy”, which they “expect the Government” to do.

He also made a reference to the current film about wartime leader Winston Churchill, as he accused pro-EU MPs of unjustified negativity, telling them: “I have been to see Darkest Hour.”

The analysis was so secret that only certain cabinet ministers were allowed to see it – and only then through individual briefings and with paper copies, to ensure the research did not leave the room.

Instead, in apparent evidence of discontent within Mr Davis’s department, the document was handed to BuzzFeed News.

A no-deal Brexit, leaving Britain trading with Europe on World Trade Organisation terms, would reduce growth by 8 per cent over 15 years compared with current projections, it found.

Leaving with a Canada-style free trade agreement would see growth cut by 5 per cent, while staying inside the single market would reduce growth by 2 per cent.

The document also warned that the gains from free trade deals with other big countries would fail to make up for the losses – a boost of just 0.2 per cent over 15 years from a deal with the US, for example.

The Prime Minister told the weekly meeting of the Cabinet that the leaked analysis was “initial work”, not approved by ministers, which did not take in the “bespoke arrangement” she was seeking.

“No analysis was made of the bespoke agreement we seek as a matter of government policy as set out in the Florence speech,” her spokesman said.