The decision of the last government not to instruct civil servants to prepare for the possibility of Britain voting to leave the European Union amounted to "gross negligence", according to an influential committee of MPs.
Ahead of the June referendum, Downing Street maintained the line that no contingency planning was being undertaken for Brexit, beyond limited preparations by the Treasury and the Bank of England for the immediate financial aftermath of a vote to quit the EU.
But a new report by the Foreign Affairs Committee tears into the previous government's "confidence that basic planning for the practicalities of implementing Brexit could be undertaken at a leisurely pace", saying that approach was "at best naïve and at worst negligent".
Brexit: MPs launch inquiry into Whitehall’s lack of contingency planning
Former UK Trade and Investment chief warns over “complete remodelling” of Whitehall
New Department for Business, Energy and Industrial Strategy swallows up DECC and BIS — full details and reaction
The MPs say: "The previous government’s considered view not to instruct key departments, including the FCO to plan for the possibility that the electorate would vote to leave the EU amounted to gross negligence.
"It has exacerbated post-referendum uncertainty both within the UK and amongst key international partners, and made the task now facing the new government substantially more difficult."
They say that the new government has been "left to play catch-up" by the lack of preparation, with its plans "tentative and just emerging".
In the days after the vote to leave, the government assembled a team of key officials in the Cabinet Office led by former Home Office official Olly Robbins. Those staff – tasked with exploring options for Britain's EU departure – have now moved to a newly-created Department for Exiting the European Union (DEEU).
"While it is essential that the Whitehall officials with relevant expertise are identified and put at the centre of managing the exit process, this cannot come at the expense of an already overstretched FCO" – foreign affairs committee
But the committee warns that DEEU, which is already absorbing key staff from across the civil service as it begins its work, must not leave the rest of Whitehall – and particularly the Foreign and Commonwealth Office – under-resourced.
"It is expected that key personnel will be transferred from across Whitehall to support the work of the Department for Exiting the European Union," the MPs say.
"While it is essential that the Whitehall officials with relevant expertise are identified and put at the centre of managing the exit process, this cannot come at the expense of an already overstretched FCO or it will threaten other aspects of the UK’s bilateral relations with some of its most important partners."
Key FCO staff expected to be in line for transfer to the new Brexit department include those working in its European directorate, and for the UK's Brussels-based Representation to the EU team in Brussels.
The committee says that once Britain has withdrawn from the EU, those FCO staff who have moved over to the Brexit department should be allowed to come back to the Foreign Office or the Department for International Trade – also set up last week – so that their "expertise and institutional knowledge" is not lost.
Before the referendum, the committee warned that a Brexit vote would require a doubling or even trebling of the FCO's resources, and the latest report calls on new prime minister Theresa May to "give the FCO the resources it needs to fill any gaps in its capacity left by the departure of officials to other departments".
"Wildly unrealistic aspiration"
During its inquiry, the committee heard from Philip Hammond – then the foreign secretary (pictured) – who dismissed the call for a substantial increase in the FCO's budget as "a wildly unrealistic aspiration".
The MPs say they were "disappointed with the foreign secretary's attitude" and say the new administration must commit to "a substantial increase in the funding available to the FCO commensurate with the enormity of the task it now faces".
They add: "The FCO should be able to use this additional funding wherever in the world it deems necessary, on the programmes or personnel it considers essential to support the country’s reputation, security, values and prosperity through this period of transition."
Launching the report, Crispin Blunt, the Conservative MP who chairs the foreign affairs committee, said the UK needed to start sending "clear signals" to its overseas allies that it was "determined to assert our place in the world post-Brexit".
Blunt added: "This is also about the UK’s international reputation. We want to see the FCO working effectively with the new Department for International Trade and the Department for Exiting the European Union.
"Our security, prosperity, values and democracy will depend on the strength of these key departments and their working relationships. The Brexit challenge requires a fully staffed and resourced FCO. A commitment to scaling up resources and personnel would give a clear signal to allies of our priorities."
The report's criticisms of a lack of planning for Brexit echo those of the joint committee on the national security strategy, with MPs and peers last week publishing a report saying that the decision not to make contingencies "indicated the prioritisation of political interests above national security".
Meanwhile, Bernard Jenkin, chair of the separate public administration and constitutional affairs committee which is looking into Whitehall's post-referendum planning, told CSW this week that the civil service had to be "free to make whatever preparations it considers necessary" and should not "be constrained by instructions from the government".
“No prime minister should be permitted to call the bluff of the electorate unless they’re prepared to lose,” Jenkin said.
Hammond himself sought to justify the lack of preparation when he gave evidence to the foreign affairs committee earlier this month, arguing that if any planning had leaked it would have attracted claims that the government was seeking to ramp up voters' fears about the impact of Brexit.
"Throughout the referendum campaign I drew attention, as did others in the campaign, to the likely consequences of a leave vote – and the reaction that I heard was that this was scaremongering," the then-foreign secretary said.
He added: "I think if we had sought to engage departments of state in preparing evidence of the likely consequences of a leave vote and that information had found its way into the public domain that would have been seen as an unwarranted intervention in the course of the campaign."