Britain faces potential "consumer panic" and gaps in security within weeks of leaving the EU without a deal, according to an official government document obtained by Sky News.

Britons living in EU countries could start returning home and there may be law and order challenges in Northern Ireland, while the pound will fall, a slide prepared for ministers reveals.

The internal government document entitled "What this could look like on the ground" and marked "Official Sensitive" sets out what a no-deal Brexit could look like in practice.

Image: The government document obtained by Sky News

It appears to be the first time the worst case scenarios have been set out by the government in a single document.

The slide was prepared in the final weeks of then-prime minister Theresa May's time in office.


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It was shown to some cabinet members but not the whole cabinet and is understood not to have been "agreed" by ministers. It is marked: "For Discussion - Not Government Policy".

The slide attempts to summarise all the potential challenges for government, consumers and business in a no-deal Brexit, divided into three categories - the challenges on the first day, after the first fortnight and at the end of the first month.

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It comes on a day that the new Chancellor Sajid Javid announced £2.1bn of spending to mitigate no-deal plans.

The slide suggests immediate and dramatic changes to Britain's relationship, and then more more systemic problems as the weeks pass.

On day one it says that "trade and passenger flows from the UK to EU slows" because of "additional process at border", adding that "UK vessels could no longer have access to EU waters and vice versa".

In Northern Ireland, cross-border agricultural trade would "virtually stop" with other trade slowing and the legal basis for the single electricity market "falls away".

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Within the first fortnight, the document warns of "potential consumer panic and food shortages, even in areas which are not directly affected at the border".

It adds that there could be "possible friction at sea between UK/EU fishing vessels".

Within the first month, small businesses in Northern Ireland "face distress and potential law and order challenges".

It says UK nationals living in EU countries could be unable to meet EU member state residency requirements and "may start returning to UK, or ask government for help".

By the end of the first month, security could be more challenging with "heightened policing resource unsustainable, operational gaps continue to emerge".

It also says the pound could settle at a lower level and points out that analysis by the Bank of England "suggests near-term business disruption likely".

It adds: "This could result in demand for support through Kingfisher", one of the programmes drawn up by officials to boost the economy after Brexit.

A government spokesman said: "We do not comment on leaked documents."