The rules for conciliation committees can now be found in Article 294 TFEU of the Lisbon Treaty. Old rules on common decision-making are changed to the Ordinary Legislative Procedure but this may still be called co-decision in practise.
On average there have been only two conciliations committees per year since the introduction of the Lisbon Treaty in 2009.
In reality the effective negotiations take place in so-called "trialogue" meetings between the EU Council, the EU Commission and the European Parliament. This is where the compromises on important European law are worked out behind closed doors.
Most EU laws are in reality still decided by civil servants in the 275 Council working groups and in the Commission.
- In 2008 a conciliation committee was only set up once, in 2007 6 times, in 2006 10 times and on no occasion in 2005
- The EU Constitution working group on simplification feared that in an enlarged EU there may be too many representatives on conciliation committees and so it proposed a lower number of representatives. This proposal was criticised because it would mean that many nation states would not be represented when laws were finally decided behind closed doors in a conciliation committee.
Conciliation and codecision http://www.europarl.eu.int/code/default_en.htm