Britain and the European Union must build a close security partnership after Brexit to foil Islamic State militant attacks and counter Russia¡¯s malign attempts to subvert Western democracies, the head of Britain¡¯s domestic spy agency said.

Britain, as Europe¡¯s preeminent intelligence power, is seeking a new security pact with the bloc to ensure it gets continued access to secrets from major EU countries as it seeks to clinch a broader Brexit deal.

In the first public speech outside Britain by a serving head of MI5, Andrew Parker will tell an event in Berlin hosted by Germany¡¯s BfV domestic intelligence service that Islamic State militants are plotting ¡°devastating and more complex attacks.¡±