A no-deal Brexit could trigger major hold-ups at channel ports, electricity price increases, shortages of some foods and delays to medicine imports, Government documents reveal.

HGV delays of between one-and-a-half and two-and-a-half days would occur at Dover and public disorder could increase, according to Operation Yellowhammer "reasonable worst case planning assumptions" released in response to MPs voting for it to happen.

The document says: "There are likely to be significant electricity [price] increases for consumers."

It adds: "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 tensions."

The Government describes the scenario outlined in the document, part of which has been redacted, as the "reasonable worst case scenario".

On food, it warns that some fresh supplies will decrease and that "critical dependencies for the food chain" such as key ingredients "may be in shorter supply".

It says these factors would not lead to overall food shortages "but will reduce the availability and choice of products and will increase price, which could impact vulnerable groups".

The document also says: "Low-income groups will be disproportionately affected by any price rises in food and fuel."

The analysis says the flow of cross-Channel goods could be reduced to 40% of current rates on day one, with "significant disruption lasting up to six months".

"Unmitigated, this will have an impact on the supply of medicines and medical supplies," it says.

"The reliance of medicines and medical products' supply chains on the short straits crossing make them particularly vulnerable to severe extended delays."

The release of the document came as Prime Minister Boris Johnson was facing furious demands for the immediate recall of MPs to Westminster after the suspension of Parliament was ruled unlawful by Scotland's highest civil court.

In a dramatic judgment, the Court of Session in Edinburgh found ministers had stopped MPs from sitting for the "improper purpose of stymying Parliament".

It said advice given by ministers to the Queen which led to the five-week prorogation was therefore "unlawful and is thus null and of no effect".

The Government immediately announced it was lodging an appeal against the ruling with the Supreme Court, with a hearing set for Tuesday.

The document's assumptions are "as of August 2" this year, and it notes that day one after the scheduled EU exit on October 31 is a Friday, "which may not be to our advantage" and may coincide with the end of the October half-term school holidays.

The Government dossier says France will impose EU mandatory controls on UK goods "on day 1 no deal" - D1ND as the document refers to it - and have built infrastructure and IT systems to manage and process customs declarations and support a risk-based control regime.

The document says: "On D1ND, between 50-85% of HGVs travelling via the short Channel Straits may not be ready for French customs.

"The lack of trader readiness combined with limited space in French ports to hold 'unready' HGVs could reduce the flow rate to 40-60% of current levels within one day as unready HGVs will fill the ports and block flow.

"The worst disruption to the short Channel Straits might last for up to three months before it improves by a significant level to around 50-70% [due to more traders getting prepared], although there could continue to be some disruption for significantly longer.

"Disruption to flow across the short Channel Straits would also cause significant queues in Kent and delays to HGVs attempting to use the routes to travel to France.

"In a reasonable worst-case scenario, HGVs could face maximum delays of 1.5-2.5 days before being able to cross the border."

The document says UK citizens travelling to and from the EU "may be subject to increased immigration checks at EU border posts".

It warns: "This may lead to passenger delays at St Pancras, Cheriton [Channel Tunnel] and Dover where juxtaposed controls are in place.

"Dependent on the plans EU member states put in place to cope with these increased immigration checks, it is likely that delays will occur for UK arrivals and departures at EU airports and ports.

"This could cause some disruption on transport services. Travellers may decide to use alternative routes to complete their journey."

The information, which had been leaked last month, was officially released following a Commons motion put down by former Tory attorney general Dominic Grieve.

In a letter to Mr Grieve, Chancellor of the Duchy of Lancaster Michael Gove, who is overseeing no-deal planning, said the document detailed a "reasonable worst case scenario".

Mr Gove said the Government was opposed to releasing electronic communications issued by named civil servants and Government special advisers regarding the suspension of Parliament as outlined in the Commons motion.

The Minister said: "To name individuals without any regard for their rights or the consequences of doing so goes far beyond any reasonable right of Parliament under this procedure.

"It offends against basic principles of fairness and the civil service duty of care towards its employees."

The Grieve motion listed key individuals in Mr Johnson's Government, including senior adviser Dominic Cummings and director of legislative affairs Nikki da Costa.

The Yellowhammer document features 20 "key planning assumptions" and there is one which is partially redacted.

The redacted section follows on from this traffic warning: "Regional traffic disruption caused by border delays could affect fuel distribution within the local area, particularly if traffic queues in Kent block the Dartford crossing, which would disrupt fuel supply in London and the South-East.

"Customer behaviour could lead to local shortages in other parts of the country."

Shadow Brexit secretary Sir Keir Starmer said: "These documents confirm the severe risks of a no-deal Brexit, which Labour has worked so hard to block.

"It is completely irresponsible for the Government to have tried to ignore these stark warnings and prevent the public from seeing the evidence.

"Boris Johnson must now admit that he has been dishonest with the British people about the consequence of a no-deal Brexit.

"It is also now more important than ever that Parliament is recalled and has the opportunity to scrutinise these documents and take all steps necessary to stop no deal."

SNP's Westminster leader Ian Blackford said: "The UK government's very own analysis has set out plainly the devastating impact a no-deal Brexit will have on Scotland and the UK.

"From rising food and fuel costs, a hit to medicines supplies, and lengthy delays at the UK's crossings - the evidence all points to the reality that it will be ordinary people and families that will pay the price of the Tories' reckless and ideological Brexit plans.

"Time and time again the evidence has shown that there is no such thing as a good Brexit. It's high time Boris Johnson heeded his own government's findings and took the threat of a no-deal off the table once and for all.

"If Parliament was sitting then MPs would be able to question ministers on the details that have been published - instead the unelected Tory leader has shut down democracy to avoid scrutiny.

"I have written to Boris Johnson demanding he recall Parliament immediately so that MPs are able to get on with their jobs of holding the government to account and able to scrutinise its Brexit plans.

"People in Scotland are looking on in horror at the bleak Brexit Britain on offer.

"Scotland deserves the choice of a better future than the one being imposed upon it by a broken Westminster system. It is clearer than ever that the only way to properly protect Scotland's interests is by becoming an independent European nation."