GETTY A soldier guards Paris after Friday's terror attack

Following Friday's attacks in the French capital, which left at least 132 people dead following a series of shootings and suicide bombings by Islamic State (ISIS) jihadists, a never-before-used part of EU law was triggered. French President Francois Hollande invoked Article 42.7 of the EU's Lisbon Treaty, which states that if a member state "is the victim of armed aggression on its territory" then the 27 other member states are obliged to provide aid and assistance "by all the means in their power". French Defence Minister Jean-Yves Le Drian described the first-time enacting of the clause as a "political act of great significance".

Conservative MEP Daniel Hannan also questioned why France had opted for the EU article rather than Article 5 of the NATO charter, which commits each member to consider an attack against one nation to be an attack on them all. The NATO clause was used by the US in the aftermath of the 9/11 terror attacks on New York City in 2001. Mr Hannan said: "Hollande could have asked to invoke NATO's Article V. "Instead he has gone for the EU's symbolic and declaratory equivalent. Why?" Although France's action is believed unlikely to require EU states to be dragged into military interventions against their will, it once again sparked calls by federalists for Brussels to have its own defence powers.

GETTY European Commission president Jean-Claude Juncker

This may be the time to kick-start the whole issue of a European defence force French MEP Michèle Alliot Marie

Earlier this year, European Commission president Jean-Claude Juncker called for an EU army in order for the 28-nation bloc to be "taken entirely seriously". French MEP Michèle Alliot Marie this week asked her fellow members of the EU's foreign affairs committee whether "this may be the time to kick-start the whole issue of a European defence force". And last night, speaking at a conference in Brussels, Mr Juncker reiterated his desire for the EU to have its own troops. He said: "We will have to invest a lot to create a real European defence policy. It is not an immediate project, but it is an ambition."

Ukip MEP Mike Hookem, a former soldier, warned British troops "must not be dragged" into a EU army. He said: "It is inevitable that despite the EU being at fault for much of the instability in Europe right now, europhiles will use the awful events in Paris and the man hunts in France, Germany and Italy to demand further integration. "They have never hid their desire for Brussels to have a military force at their finger tips; that's only something politicians seem to do in Westminster. "Earlier this week we saw France taking the first step towards an EU response to the terror acts and leaders have jumped at the prospect. "But our Armed Forces must not be dragged into an EU military: they take an oath to Her Majesty and must remain at the sole command of Her Government." Mr Hookem also suggested further cuts to Britain's armed forces in the Government's Strategic Defence and Security Review next week would "give the excuse our military are no longer capable of taking on large military missions so we have to call on our European neighbours to help out."