Operation Yellowhammer

Operation Yellowhammer is the codename used by the UK Treasury for cross-government civil contingency planning for the possibility of a "no-deal" Brexit.[1][2][3] In the event of no-deal, the UK's unilateral departure from the EU would disrupt, for an unknown duration, many aspects of the relationship between the UK and European Union, including financial transfers, movement of people, trade, customs and other regulations.[4] Operation Yellowhammer is intended to mitigate, within the UK, the effects of this disruption,[2] and would be expected to run for approximately three months.[5] It has been developed by the Civil Contingencies Secretariat (CCS), a department of the Cabinet Office responsible for emergency planning.

Disclosure and naming[]

The existence of the operation leaked on 6 September 2018, when a press photographer captured a snapshot of a document revealing some "no-deal" plans and the HM Treasury codename for them.[6] The document appeared to indicate the CCS had been used in anticipation of government policy.[7] No further details were revealed. The National Audit Office subsequently made public some documents about the operation.[8]

The operation code name "Yellowhammer", which relates to a small songbird, was chosen at random.[9]

On 2 February 2019, The Times received leaked documents with this code name, about Department for Transport command and control structure plans.[10][2]


Operation Yellowhammer covers actions to be taken in a no-deal scenario,[1] some of which would be implemented prior to the date of leaving.[2]

On 29 January 2019 the House of Commons voted, in a non-binding ballot, to reject a no-deal Brexit.[11] However, unless the House of Commons were to accept the Brexit withdrawal agreement, or the EU's other members were to grant the UK an extension under Article 50 of the Lisbon Treaty, or the UK were to revoke its Article 50 notice, the United Kingdom would by default exit the EU on 29 March 2019 with no deal.[12]

On 20 March 2019, Kent county council activated plans to keep roads, hospitals and schools open, and the UK government's Brexit secretary, Steve Barclay, said that Operation Yellowhammer command and control structures would be "enacted fully" on 25 March 2019 unless a new exit date was agreed between the UK and the EU.[2][13] On 21 March 2019, the Ministry of Defence staffed a bunker under its Whitehall headquarters to coordinate no-deal related military activities under Operation Redfold,[5] and the Cobra emergency committee took control of no-deal planning with intentions to implement national contingency plans on 25 March 2019.[14][15][Note 1]

Late on 21 March 2019, possible new exit dates were agreed between the UK and the EU:

Consequently, full activation of Operation Yellowhammer was postponed until 8 April 2019.[18][19]

EU Preparedness[]

The European Union issued a press release on 25 March 2019 indicating it had completed preparations for an increasingly likely "no-deal" scenario on 12 April 2019.[20]


Operation Yellowhammer was developed by the CCS though Cobra took control on 25 March 2019.[14] This will be organised via a Command and control structure (C3).[14] This will co-ordinate:[14]

  • If a Government department's contingency plans are inadequate Operation Yellowhammer will take over planning and decisions for that department.

Major decisions will be taken by the European Union Exit and Trade (Preparedness) sub-Committee, set up in January 2019[21] and chaired by the prime minister. It will have wide-ranging powers to order emergency measures, including use of the military, and overriding regulations.[5]


The CCS may work with the Department for Exiting the European Union (DExEU) to achieve an objective for Brexit work, with the DDxEU concentracting on new policies, legislative changes and required funding changes with the CCS dealing with steps to mitigate and manage short term disruption. An example objective would be Continuity of supply of medicines into the UK after no deal exit from the EU falling within the areas of risk of key goods crossing borders and transport systems. Arrangements for prioritisation of key goods, additional ferry capacity and having procedures in place for operation customs operations that are effective immediately from the Brexit date are some of the areas covered.[8]:15

Areas of risk[]

Operation Yellowhammer identifies 12 areas of risk. These include medicine supply chain and UK citizens in the EU.[2] There are also three risks common to all areas.[8] :7

The twelve areas of risk are:[8]:7

Risks common to all areas:[8]:7

Costs and resources[]

In March 2019 the CCS had 56 people working internally on the programme; it is estimated 140 would be needed to maintain the operations centre and it has been budgeted to cost £1.1 million in 2018–2019. This is in the context of the UK Treasury allocating £1.5 billion for Brexit preparations by government departments in 2018–2019.[14]

3,500 troops are on standby to assist in the event of a no-deal exit, although the Ministry of Defence has only disclosed their mission will be to "support government planning".[5][22]


On 21 March 2019, the UK government's decision to risk a no-deal Brexit and to invoke Operation Yellowhammer was criticised by the First Minister of Scotland, Nicola Sturgeon.[23] Her sentiments were echoed by the First Minister of Wales, Mark Drakeford.[24] On 22 March confidential Cabinet documents on Operation Yellowhammer were obtained by The Guardian newspaper. The document warned that ministers could need to work 22.5-hour days,[25] and departments would have to work 24 hours a day for at least twelve weeks without input from higher up in government. A source with knowledge of the operation said that, although planning had stepped up, the overall picture remained chaotic and "rudderless".[5]

See also[]

Notes and references[]


  1. ^ This announcement was made prior to changed circumstance of the EU offering extensions to the article 50 exit date late on 21 March 2019.
  2. ^ The House of Commons has did not approve the withdrawal agreement by 29 March 2019 leaving the default legal position that the UK is to exit the EU on 12 April 2019.


  1. ^ a b "Operation Yellowhammer: Photo of secret government no-deal Brexit papers reveals questions over 'rail access to the EU". The Independent. 6 September 2018. Archived from the original on 6 September 2018. Retrieved 6 September 2018.
  2. ^ a b c d e f correspondent, Lisa O'Carroll Brexit (20 March 2019). "UK's emergency plans for no-deal Brexit begin to be put into action". The Guardian. ISSN 0261-3077. Archived from the original on 20 March 2019. Retrieved 20 March 2019.
  3. ^ "MoD hosts no-deal planning in bunker". BBC News. 21 March 2019. Retrieved 22 March 2019.
  4. ^ Morris, Chris (14 October 2017). "Brexit: What would 'no deal' look like?". BBC. Archived from the original on 24 October 2018. Retrieved 6 September 2018.
  5. ^ a b c d e f Nick Hopkins (22 March 2019). "Secret Cabinet Office document reveals chaotic planning for no-deal Brexit". The Guardian. Archived from the original on 23 March 2019.
  6. ^ Kuenssberg, Laura (6 September 2018). "Snatched pic gives insight into 'no deal' Brexit planning". Archived from the original on 6 September 2018. Retrieved 6 September 2018.
  7. ^ Islam, Faisal. "It's been another first for Brexit". Sky. Archived from the original on 6 September 2018. Retrieved 7 September 2018.
  8. ^ a b c d e National Audit Office - Cabinet Office Civil Contingencies Secretariat (12 March 2019). "Contingency preparations for exiting the EU with no deal" (PDF).
  9. ^ Wright, Oliver (7 September 2018). "Prepare for cuts under no-deal Brexit, Treasury tells Whitehall in Operation Yellowhammer". The Times. Retrieved 22 March 2019.
  10. ^ @SamCoatesTimes (2 February 2019). "37 page "Operation Yellowhammer" no deal planning pack for staff leaks. Marked "official sensitive"" (Tweet). Retrieved 2 February 2019 – via Twitter.
  11. ^ "Brexit: How did my MP vote on the amendments?". BBC. 29 January 2019. MPs vote to reject leaving without a deal. Archived from the original on 6 February 2019. Retrieved 20 March 2019.
  12. ^ Morris, Chris (20 March 2019). "Brexit delay: How can Article 50 be extended?". BBC. Archived from the original on 2 February 2019. Retrieved 21 March 2019.
  13. ^ Zeffman, Henry; Wright, Oliver (21 March 2019). "Brexit vote: Cobra takes over planning for no-deal". The Times. Retrieved 21 March 2019.
  14. ^ a b c d e f Guyoncourt, Sally (21 March 2019). "Operation Yellowhammer: what are the Government's emergency plans for a no-deal Brexit and how would they work?". inews.co.uk. Archived from the original on 22 March 2019.
  15. ^ "Brexit: Govt preparing to enter 'very high readiness mode' for no deal". Sky News. Retrieved 22 March 2019.
  16. ^ "EU leaders agree Brexit delay plan". BBC News. 22 March 2019. Retrieved 22 March 2019.
  17. ^ Adler, Katya (22 March 2019). "Brexit pushed back by at least two weeks". BBC News. Retrieved 22 March 2019.
  18. ^ Zeffman, Henry (23 March 2019). "No-deal emergency plan is put on ice after Brexit delay". The Times. Retrieved 29 March 2019.
  19. ^ "Operation Yellowhammer: departments told not to overload central command - Civil Service World". www.civilserviceworld.com.
  20. ^ "Daily News – 25.03.2019". European commission Press Release Database. Archived from the original on 25 March 2019.
  21. ^ David Lidington (8 January 2019). "Cabinet Committees and Implementation Task Forces:Written statement - HCWS1238". UK Parliament. Retrieved 22 March 2019.
  22. ^ Edgington, Tom; Schraer, Rachel (23 March 2019). "No-deal Brexit: What is the UK government doing to prepare?". BBC. Archived from the original on 23 March 2019.
  23. ^ "Meeting of the Parliament 21 March 2019 [Draft]". On operation yellowhammer, which is the emergency planning for a no-deal Brexit, it is beyond comprehension that any Prime Minister could knowingly allow the country to be eight days—about 200 hours—away from the possibility of crashing out of the European Union without a deal and to require that emergency planning work to be done.
  24. ^ Melanie May (22 March 2019). "First Minister tells charities to put aside normal activities and plan for No Deal". Fundraising.co.uk. Retrieved 22 March 2019.
  25. ^ "'Leaked' plans for no-deal Brexit reveal how chaotic it could really be". 22 March 2019.

External links[]

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Subnational level[]