Operation Yellowhammer: departments told not to overload central command

Confidential document warns no-deal "structure will quickly fall if too many decisions are unnecessarily escalated to the top levels"

The government's no-deal contingency planning is dubbed Operation Yellowhammer. Photo: PA

By David Blackman

25 Mar 2019

The government has postponed activating no-deal Brexit contingency plans until next month as a Whitehall internal document warns that its ‘Operation Yellowhammer’ central unit could be overwhelmed by too many departmental decisions being referred up the line.

According to a report in The Times, the “command and control” structures of Operation Yellowhammer, the civil service’s no-deal Brexit planning unit, had been set to be “enacted fully” today.

Cobra, the government’s emergency committee, would then have taken control of the process.


However, officials have been told that Yellowhammer will now not be activated until 8 April, according to the newspaper.

This ties in with the revised the Brexit date of 12 April, which was fixed at last week’s EU Council of Ministers summit, if the government’s Brexit withdrawal deal has not been passed by the House of Commons.

The delay emerged as the Guardian published details of Whitehall contingency plans, which warns departments against overloading Operation Yellowhammer by referring too many decisions to the pan-Whitehall unit.

A confidential Cabinet Office document, seen by the newspaper, states that “the … structure will quickly fall if too many decisions are unnecessarily escalated to the top levels that could have reasonably been dealt with internally.”

It also says that Operation Yellowhammer will be unable to predict the likely “unforeseen issues and impacts” of no deal.

A flowchart of a routine ‘no-deal' day in Whitehall shows that assessments and meetings would be sent to ministers and senior officials nearly round the clock from across the UK, kicking off at 7am.

In a bid to mitigate the potential disruption resulting from a no-deal Brexit, the Cabinet Office has devised a “high-level concept of operations” manual for Whitehall command, control and coordination of any problems that are likely to arise, the Guardian reported.

The document warns agencies and government departments that they will be working 24 hours a day during the “critical phase” immediately post-Brexit, which will last for at least twelve weeks and up to 24 for some.

Twelve high-risk areas have been identified as being of particular concern including transport, healthcare services, and food and water supplies.

The weekend also saw calls by ex-senior officials and politicians for a Chilcott-style public inquiry into the government’s handling of the referendum and the EU withdrawal process.

Tom Watson, deputy leader of the Labour Party, told the Observer yesterday that a “detailed postmortem” would be required into the UK’s EU withdrawal, while Lord Kerslake, former head of the home civil service, said that the probe should “probably be a 'judge led' inquiry”.

Kerslake told Radio 4’s Westminster Hour programme that an inquiry could be “cathartic” in healing the wounds opened up by the “cataclysmic and traumatic” Brexit process.

Lord Ricketts, former permanent secretary at the Foreign Office and national security adviser, called for a “searching” inquiry. Adding that the UK has got itself in a “fantastic mess”, Ricketts said there was a case for looking at the advice ministers were given and how they reacted to it, how government had worked during the process and the use of public money for no deal planning.

CSW has approached the Cabinet Office for a comment.

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