Pillar three relates to justice and home affairs (JHA), another highly sensitive political area. As such, decision-making under pillar three continues to be primarily intergovernmental.
This is probably the least developed area of EU common policy, because of the cultural and legal barriers to harmonisation and the implications it has for national sovereignty.
Indeed, the Amsterdam Treaty reduced the scope of pillar three to 'police and judicial cooperation in criminal matters' – while it transferred immigration, asylum and refugee policy to pillar one, under the Schengen agreement, the UK, Ireland and Denmark secured the right to opt out from these provisions.
Under pillar three, either the commission or member states can bring forward policy proposals, which are presented to the council for consideration.
The council then takes responsibility for drawing up conventions, which can only be adopted on the basis of unanimity.