The failed terrorist attack on the Amsterdam-Paris Thalys has prompted the outspoken group leader of the Alliance of Liberals and Democrats for Europe, Guy Verhofstadt, to reiterate his demand for a European Intelligence Agency.
His comments come as it emerges that the attacker, Ayoub el Khazzan, was allowed to travel freely around Europe despite being known to French, Belgian, German and Spanish intelligence services.
Verhofstadt, a committed federalist, believes the attack demonstrates how important it is, "that national intelligence agencies in the EU share information and work more closely together.
"In most major terrorist attacks over the past ten years, the perpetrators were known, but EU countries haven’t always worked together effectively to identify imminent security threats. A solution to this could be a fully-fledged EU intelligence agency.
"The Charlie Hebdo shooting earlier this year, and last week’s Thalys attack, highlight that the terrorist threat is increasingly "home-grown". To defeat this we must urgently agree a mechanism to better share intelligence across the EU."
Verhofstadt is not the only high profile figure to petition for a European Intelligence Agency.
Pietro de Matteis, President of the European Federalist Party, argues that, "a functioning European Intelligence Service" would "prevent that person jumping on a train with the gun in the first place."
However, European officials urged caution against overreaction. Commission transport spokesman, Jakub Adamowicz, highlighted the costs and logistical problems associated with tighter security. He suggested a "hyperactive" response may prove "counterproductive."
Eurosceptic MEPs have also rejected demands for a European Intelligence Agency, arguing security services are the prerogative of member states.
Geoffrey Van Orden, an ex-military intelligence officer and the British Conservative party spokesperson on security and defence, told Parliament Magazine:
"If you accept the concept of a state called Europe, of course you want it to have all the instruments of statehood - not just a central government, but also a diplomatic service, armed forces and intelligence and security services. We reject this concept.
"Naturally, those such as Guy Verhofstadt, who inhabit the curious world of euro-federalism, cannot wait to get their hands on these most sensitive areas of sovereign national interest and responsibility."
Regardless of opinion, it is clear that the security situation needs to be resolved.
A combination of the migration crisis and a heightened terrorist threat has led several prominent politicians to question the Schengen agreement – one of the cornerstones of the European project.
German Chancellor Angela Merkel, has warned that "If it’s not possible to achieve a fair allocation of refugees within Europe, then some people will want to put Schengen on the agenda."
Meanwhile Charles Michel, the Belgian Prime Minister, has gone further, urging policymakers to consider reintroducing identity and luggage inspections across international train routes.
In reality this is unlikely to happen. On Saturday, European ministers supported implementing tighter security measures across Europe’s rail network with only a ‘targeted modification’ to the Schengen agreement.