Theresa May will today warn the European Union that lives will be put at risk if it lets its "deep-seated ideology" act as a barrier to a new post-Brexit security treaty.

In a landmark speech in Munich the Prime Minister will say that there will be "damaging real world consequences" if it puts "political doctrine" before co-operation on security.

The EU is threatening to bar Britain from joining the European Arrest Warrant and limit access to a European police database containing information about criminals and terrorists after Brexit.

Its approach is being viewed with increasing concern by member states, who believe that co-operation with Britain's world-class security services is vital.

The heads of security services in Britain, Germany and France yesterday took the extraordinary step of issuing a joint warning that continued intelligence co-operation is "indispensible" after Brexit.

The Prime Minister's speech in Munich this morning comes moments before Jean-Claude Juncker, the President of the European Commission, takes to the stage.