Defence Ministers have been questioned in Parliament on the impact Brexit could have on the defence industry.
MPs have been expressing their fears over the impact of Brexit on EU defence relationships and on the UK's defence industry.
It came as contingency planning continued for the possibility of Britain crashing out of the EU.
At the Ministry of Defence (MOD), preparation for a no-deal scenario is ongoing.
Operation Redfold, the military’s contingency planning operation, is preparing to respond to whichever government department needs help in the event of a no-deal Brexit.
The former RAF base at Manston in Kent could also be used.
The runways could become a 6,500-space lorry park for those HGVs who get caught in a log jam as the free movement of goods comes to an end.
On the M20, Operation Brock was tested yesterday.
One side of the motorway was reserved as space for a backlog of HGVs heading for Europe, whilst traffic was diverted onto the other carriageway.
The impact of Brexit and its effect on defence is weighing heavily on some MPs' minds, and they brought their questions to Parliament on Monday.
The Prime Minister told the House on Monday: "Unless this House agrees to it, no-deal will not happen, No Brexit must not happen, and a slow Brexit - which extends Article 50 beyond 22 of May, forces the British people to take part in European elections and gives up control of any of our borders, money or trade is not a Brexit that will bring the British people together.
"I know the deal I have put forward is a compromise, it seeks to deliver on the referendum and retain trust in our democracy whilst also respecting the concerns of those who voted to remain.
"But if this house can back it, we could be out of the European Union in two months.
"There will be no further extensions, no threat to Brexit, and no risk of a no-deal.
"That, I believe, is the way to deliver the Brexit the British people voted for and I commend this statement to the House."
Watch: the defence industry plays a crucial role in the economy.
The defence industry supports 260,000 jobs, contributing on average 7 billion in exports each year, according to the MOD.
But even with disruption, experts say defence supply chains are interlinked and that the risk of trade damage is low.