The UK's Ministry of Defence has reportedly taken over a nuclear bunker below its offices in central London to set up an armed forces command centre to fine-tune its military readiness of any chaotic fallout in the event that Britain and the EU fail to strike a deal for an orderly transition at the borders.
The room beneath Whitehall, which is already used for crisis management throughout the year, would be used to coordinate efforts in the event of a no-deal Brexit to ensure the smooth movement of goods and people.
The MoD's Operation Redfold is reportedly the military element of the wider UK government no-deal planning that is labelled Operation Yellowhammer.
It comes as Cobra, the UK government's emergency committee, has taken over control of Operation Yellowhammer from the Cabinet Office to start implementing contingency measures from Monday.
Almost 1,000 MoD civil servants are on standby to help other government departments, following formal requests for assistance.
An MoD spokesperson said the ministry was "always willing to support wider government planning for any scenario".
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"We have committed to holding 3,500 troops at readiness to aid contingency plans. We will consider any requests from other government departments if they feel defence capability could contribute to their no-deal planning," the spokesperson said.
UK Defence Secretary Gavin Williamson had said in December last year that troops would remain at high readiness to assist with transport and logistics.
The sheer uncertainty of what might unfold in the event that the UK and EU fail to sign up to an agreed set of arrangements in time for Britain's exit has meant that the preparations have had to cover a broad range of subjects to ensure there is no disruption to the supplies of essentials regularly transported seamlessly across the borders of the 28 EU member-countries.
The UK has secured a short delay to the March 29 Brexit deadline after the EU leaders reluctantly agreed to offer embattled Prime Minister Theresa May time until May 22 to get the divorce deal through another House of Commons vote next week.
If the agreement, already defeated twice over the controversial Irish backstop clause, fails to clear the UK Parliament for a third time, the EU has set April 12 as the deadline for Britain to make up its mind on the next move.