Data sharing with European Union nations will not change even if there is a no-deal Brexit, senior members of British intelligence and defence have said.
GCHQ director Jeremy Fleming warned that an agreement still needed to be reached with the EU around data adequacy, a status granted by the European Commission allowing a free flow of data between European Economic Area (EEA) countries and those outside it.
However, Mr Fleming said the UK is operating "even more closely" with European counterparts now than it was at the point of the 2016 referendum.
The GCHQ chief was speaking at a Chatham House event alongside General Sir Patrick Sanders, Commander Strategic Command, about the UK’s National Cyber Force, a joint MI6 and military effort to combat the growing threat of hostile states, terrorists and criminals online.
Gen Sanders said the relationship with key EU allies is "strong enough to withstand any of the strain and tension that may arise" after 31 December in terms of defence and security.
"It’s no secret that the UK is one of the two leading powers in defence and security of Europe and that regardless of the outcome on the 1st of January that won't change and our relationships with our European partners and a few, in particular, is strong enough to withstand any of the strain and tension that may arise as a result of that," he explained.
"When it comes to all the defence and security aspects that I’m involved with, those links will not change and if anything they will be as strong, and of course NATO is the critical but not the only vehicle."
Mr Fleming said: "It is the case that today we are operating even more closely with our European colleagues than we were at the point of the referendum and we do that because there’s great national self-interest in close cooperation and I fully expect that to be the case the 1st of January, deal or no deal.
"We need to reach an agreement with the EU around data adequacy, it is the UK’s position that our arrangements – obviously because they have been developed whilst we were in the European Union – are adequate in so far as the EU is concerned going forward and we just need to nail that down, but I think that can be a relatively straightforward thing."