Operation Yellowhammer is a government dossier outlining what could happen if Britain leaves the European Union without a deal in place.
The government was forced to disclose the five-page document after MPs voted in Parliament to make it public.
Number 10 has maintained that the 20 “key planning assumptions” are for a “reasonable worst case” scenario.
Defence Secretary Ben Wallace told talkRADIO that he was confident that “99.9 per cent, or most” of the warnings will not happen because the government is working to “properly prepare for no-deal and put resource behind that planning”.
Downing Street has been criticised for only releasing a redacted version of the dossier, in which one of the assessments is missing.
So, what did the controversial document say?
The document predicts delays in trade and travel.
It said if France imposes compulsory EU controls on goods, disruption at the Channel ports could last for up to three months, but could continue for “significantly longer”.
Meanwhile, Britons travelling to and from the EU may see increased immigration checks at EU border posts which could result in passenger delays at the Channel Tunnel and UK arrivals and departures at EU airports and ports.
The document continued to say that medicines and medical products are “particularly vulnerable” to severe extended delays, with three-quarters of medicines relying on affected ports.
It warned that the shelf life of medicines means it is “not practical” to stockpile in preparation for delays that could last up to six months.
It also said that disruption to supply of animal medications would “reduce our ability to prevent and control disease outbreaks”, which it said could have “detrimental impacts” for animal health, the environment and food safety, directly impacting human health.
Food and energy
Operation Yellowhammer said that it did not expect overall food shortages but that certain types of fresh food supplies will decrease, which will increase prices and could increase the risk of panic buying.
Electricity and gas supplies will not be disrupted but again there is “likely to be significant electricity price increases for consumers”.
It highlighted that low income groups will be “disproportionately affected by any price rises in food and fuel” – which Jeremy Corbyn said showed “Boris Johnson is prepared to punish those who can least afford it”.
Public water services will be largely unaffected.
Civil unrest was another concern highlighted.
It read: “Protests and counter-protests will take place across the UK and may absorb significant amounts of police resource.
“There may also be a rise in public disorder and community tenisons.”
The document indicated that measures in place with the aim of avoiding a hard border in Northern Ireland may be "unsustainable".
It read: “The automatic application of the EU tariff and regulatory requirements for goods entering Ireland will severely disrupt trade."
The agri-food sector is set to be the “hardest hit” while disruption to key sectors and job losses are “likely to result in protests”.