The Prime Minister's draft Brexit withdrawal agreement was unveiled last week yet it is still not completely clear how defence will be affected (Cover Picture: MOD).
The British military are thought to be preparing plans to assist the emergency services in the event of a no-deal Brexit.
The Ministry of Defence (MOD) said that it "routinely works with other Government departments on planning for a range of contingency scenarios", in response to the reports.
Last year, the Armed Forces were called out to support civil authorities in the aftermath of terrorist attacks, known as Operation Temperer.
Speaking in London on Monday morning, the Prime Minister said of the withdrawal from the European Union: "It was never going to be easy or straightforward, and the final stage was always going to be the toughest.
"But we have in view a deal that will work for the UK, and let no one be in any doubt – I am determined to deliver it."
However, if Theresa May cannot get it through parliament, it would raise the possibility of the UK crashing out of the EU in March 2019.
A no-deal outcome could result in large amounts of disruption at ports and airports, with food and fuel supplies affected.
It is at this point when the military could be asked to provide crisis support, as they did during fires on Saddleworth Moor over the summer.
In a no-deal scenario, their efforts could range from managing traffic stacked up on the motorway to Dover, to helping police keep order in the event of major shortages.
It is likely they are also planning for less extreme scenarios – where they offer support in a much less visible way.
What will Brexit mean for defence?
Does Brexit matter to British defence while the UK is part of NATO? Will Brexit mean a 'European Army' is more likely? We asked two defence experts for some of the answers... More: https://www.forces.net/news/what-does-draft-brexit-agreement-mean-defence-personnelPosted by Forces News on Monday, 19 November 2018
We asked two defence experts for some of the answers around Brexit and defence
Major General (Ret'd) Chip Chapman, former Head of Counter Terrorism at the Ministry of Defence, outlined why it was necessary to prepare for a no-deal Brexit: "If it was just general duty manpower, substitution manpower for the police for example, in breakdown of law and order there would be no additional training requirement placed upon people.
"If you had to generate additional capabilities such as drivers or things like that, then there would be a training period required.
"That is why it would be sensible to make contingencies if the government think that there are going to be these scenarios where military aid might be required."
What are the practicalities for serving military personnel post-Brexit?
It is far from unprecedented to see the forces helping civilian authorities – their role delivering some of the security at the London 2012 Olympics earned them many plaudits.
The MOD says it routinely works with other government departments planning for a range of contingency scenarios.