The civil service will "largely" need to reallocate existing staff rather than hire new ones as Britain leaves the European Union, former Cabinet Office minister Oliver Letwin has said, after a leaked memo said headcount may have to rise by up to 30,000 to cope with the extra pressure of Brexit.
The Times on Tuesday published what it said was a memo on Brexit prepared for the Cabinet Office by a consultancy firm, which included details on civil service capability and resources.
Downing Street has already pushed back strongly against the report, saying it appeared to be an attempt by accountancy firm Deloitte to pitch for government work.
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According to the report, one department is pushing for a 40% increase in staff to cope with the extra demands of Brexit – and there are "expectations of increased headcount" across the civil service ranging from 10,000 to 30,000.
The memo also says efforts to build civil service firepower to cope with Brexit are making only "slow progress" because of "deliberate control by the Cabinet Office" and the Treasury's view "that departments will meet Brexit costs from existing settlements".
And it says departments should not expect an injection of fresh resources at next week's Autumn Statement.
Letwin, who served as Cabinet Office minister and a key policy thinker throughout David Cameron's time as prime minister, said Brexit was "clearly a huge challenge" for the civil service, but he added: "I don't think we needed a memo to tell us those things."
Speaking to the BBC's World at One, the Tory MP said he believed departments could meet the demands of Brexit by moving existing officials around.
And he said there would be only "relatively rare" instances, including taking on trade negotiators, in which new hires would be needed.
"I think one needs to distinguish between two different propositions," he said. "Is there a need for civil servants to be working specifically on the issues related to exiting the EU. The answer? Evidently yes, in quite large numbers. I don't know what the numbers will turn out to be, but quite large.
"The second proposition is there a need to add to the total number of civil servants in order to be able to staff up this function? I very much doubt it. "
He added: "My experience in Whitehall was that if you kept pressing, you kept finding areas in which the government was doing things that it didn't need to do as much of, and therefore, I suspect that if the right imagination is used it will be perfectly possible to reallocate, largely."
Letwin also downplayed talk of cabinet splits over the Brexit process, after the memo said permanent secretaries in government departments were unable to get on with "realistic planning" because ministers had yet to come up with an agreed negotiating position for withdrawal talks.
The former Cabinet Office minister said in his experience, stories about division were often the result of "serious, grown-up people sitting around the table and talking about things and sorting them out".
"I suspect that if the right imagination is used it will be perfectly possible to reallocate" – former Cabinet Office minister Oliver Letwin
Letwin's view that departments can meet the Brexit challenge with existing resources echoes the message sent out by civil service chief executive John Manzoni in recent days.
Manzoni told a seminar last week that government was already doing "30% too much" before the Brexit vote, and said departments would need to re-prioritise in the wake of the vote to leave.
Theresa May has, he said, already told departmental leaders that the "fiscal context won't change" in light of the vote to leave the European Union.
"What Whitehall does not have is the capacity to deliver Brexit on top of everything else to which it is already committed," Joe Owen, the Institute for Government
"The fact is we need to go back, we need to re-plan, we need to be realistic, we can't do it all – it won't all happen within the existing envelope," Manzoni said.
Memo has "not been commissioned by government"
Meanwhile the source of the memo itself continued to be the subject of debate, as Theresa May's spokeswoman said the briefing shared with The Times had not formed part of any official government work, and took the extraordinary step of pointing the finger at Deloitte.
"This individual has never been in Number 10 or engaged with officials in Number 10 since the prime minister took office," she said.
"It is really for Deloitte to answer what it is about. 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."
But The Times journalist behind the story, Deborah Haynes, has stood by the report.
She tweeted on Tuesday: "Brexit memo was seen and aided by senior civil servants. @Number10gov should stop shooting the messenger and start addressing the challenges."
Joe Owen, a researcher for the Institute for Government think tank, meanwhile said that although the IfG "may not recognise the numbers in this memo, we recognise some of the claims".
"What Whitehall does not have is the capacity to deliver Brexit on top of everything else to which it is already committed," he wrote on the IfG's blog.
"The work required to deliver Brexit has been described to us as an ‘existential threat’ to how some departments operate. Managing this whilst continuing to deliver existing priorities with the smallest civil service in decades is unsustainable."
Owen pointed out that some departments, such as Defra, are already in the middle of transformation programmes that seemed "ambitious before Brexit came along", as he repeated the IfG's call for government to set out a fresh list of priorities in response to the vote.
"There are departments upon which Brexit will have a huge impact," he said. "We hope the Autumn Statement will show the commitments the government intends to keep, and what it will drop, so resources can be focused on the Brexit task."