Downing Street has dismissed a leaked memo that suggested the Conservative Government has no plan for Brexit.
The document warned Cabinet splits were delaying the UK administration’s ability to agree a negotiating strategy.
It also identified “well over 500 projects” being undertaken by Whitehall departments to implement Brexit, creating the need for up to 30,000 extra civil servants.
But a UK Government spokesman described the memo as “unsolicited” and insisted it had no authority.
He disputed claims it was written by a consultant working for the Cabinet Office, adding: “It was produced by an individual from an external accountancy firm.”
The memo – reportedly dated November 7 and entitled Brexit update – provoked a barrage of comments from opposition politicians who characterised it as proof of the “chaos” behind the scenes.
North-east MSP Lewis Macdonald, who is Scottish Labour’s Europe spokesman, said it simply wasn’t good enough five months after the EU referendum.
He added: “The Tories’ reckless Brexit gamble means so much uncertainty for Scotland’s economy and public services.
“Theresa May is presiding over a right-wing Cabinet that is engaged in a civil war, while voters have been left in the dark.”
SNP MP Stephen Gethins, his party’s spokesman on Europe, said it had become “pristinely evident” the UK Government’s repeated refusal to provide a running commentary was because there was no plan to comment on.
He added: “This leaked memo offers a staggering insight into the utter confusion and chaos that dominates the shambolic Tory party right to the very top.
“Theresa May can no longer expect to blindly push the UK to the brink with clouded rhetoric on the Tories’ ideological pursuing of a hard right Brexit.”
But a UK Government spokesman said: “It (the memo) has no authority and we don’t recognise any of the claims it makes. We are getting on with the job of delivering Brexit and making a success of it.”
Mrs May’s official spokeswoman later said the prime minister had not been aware of the document’s existence.
She added: “Certainly it has not been commissioned by government, it’s nothing to do with us. It hasn’t been distributed widely across government. It does seem as though this is a firm touting for business.”
Meanwhile, as the criticism flooded in, the prime minister received an unexpected boost from Labour, which has pledged not to block or delay the triggering of Article 50.
In a speech in London, shadow chancellor John McDonnell said: “We must not try to re-fight the referendum or push for a second vote. And if Article 50 needs to be triggered in parliament, Labour will not seek to block or delay it.
“To do so would put us against the majority will of the British people and on the side of certain corporate elites, who have always had the British people at the back of the queue.”
A Deloitte spokesman later said its note was “intended primarily for internal audiences”.
He added: “It was not commissioned by the Cabinet Office, nor any other government department, and represents a view of the task facing Whitehall.
“This work was conducted without access to Number 10 or input from any other government departments.”