It was reported last month that personnel could assist the emergency services in the event of a no-deal Brexit (Picture: MOD).
Defence Secretary Gavin Williamson has said 3,500 troops will be "held at readiness" to help with a no-deal Brexit.
Speaking in the House of Commons, he said: "We've as yet not had any formal request from any Government department but what we are doing is putting contingency plans in place.
"What we will do is have 3,500 service personnel held at readiness - including regulars and reserves - in order to support any Government department on any contingencies they may need."
Mr Williamson was replying to Tory MP Will Quince, who asked him to confirm if there had been approaches from other Government departments about using the UK's "world-class armed forces personnel in the event of a no-deal Brexit".
The Defence Secretary had earlier announced further details from the Modernising Defence Programme to the Commons.
What role could the military play in the event of a no-deal Brexit?
Last month, the Defence Secretary announced that three Royal Navy patrol ships will be retained to protect UK home waters after leaving the European Union.
The Offshore Patrols Vessels (OPVs), HMS Tyne, HMS Mersey and HMS Severn supported the Fishery Protection Squadron.
All three vessels will be part of the fleet, with funds announced earlier this year by the Chancellor going towards maintaining them ready for service.
In November, a think tank warned the European Union was "out of its depth" when it comes to its defence ambitions, even with British participation.