The procedure is foremost legislative procedure and govern by rules listed in Art. 294 of TFEU. Earlier known as co-decision procedure (Art. 251 EC) when it was proposed in the Maastricht Treaty. In relations to role of European parliament (EP), it has equal footing with council. There are up to three main stages.
Primarily, European Commission (EC) has the right to initiate legislative proposal upon its own initiative or by the request of other MS or institutions, respected by citizen’s initiative. Next, proposal will be sent to EP, Council, national parliament, and sometimes to committee of regions and the Economic & Social Committee. First reading by EP which President of parliament raises proposal to parliamentary committee which then discuss and vote on the legislative in plenary, resulted in EP’s position. The institutions can accept without any amendment. Then, it will be dispatched to Council. Meanwhile on the first reading, council merely conduct their reading based on EP’s position. They can either accept, resulted in proposal being adopted- or amend EP’s position which constitute as council first reading. It will be sent to Parliament for second reading
In the second reading, EP has three to four months to examine the council position and this process have four possible aftermaths. First, EP approves position of council and the act is adopted. Second, EP fails to take decision within the time frame meaning the act adopted based on the council first reading. Third, EP reject council first reading and the act cannot be adopted and procedure ended. Lastly, EP propose amendments to council first reading and dispatch the position to Council for second reading. Similarly, the council has the same time-limit to assess EP’s second position. It is also informed about the Commissions position on the parliament second reading. What council can do in these steps is either to approve all parliament’s amendments or reject it. Rejection of EP’s amendment will have formed a meeting of Conciliation Committee consisted of President of Council and Parliament president. In the following steps, second reading, EP has up to four months to assess the position of council. It has few possible results. First, when EP approve the council position and act is adopted. Second, in case parliament fails to take decision within time limit, means the act adopted based on council first reading. Third, EP reject and procedure ended. Lastly, EP makes amendments and dispatch it to council for their second reading. The Council has same time limit to assess EP’s second reading and they either can approve or reject it. If rejection arise, then conciliation committee must be formed.
Conciliation Committee must be created within eight-week post council second reading rejection, which consist of even number of Council and MEP’s and chaired by European Commission to agree on joint text. If this step ineffective, the procedure ended. But if agreement has been reached, text will be referred to third reading of Council & EP. Lastly, within same time limit, both bodies have to decide and modify. If one rejects or doesn’t decide within time limit, the procedure ended without any legislative being adopted. EP has the right to veto
In terms of number of legislation which decided by the procedure, 67% of the case concluded in the first reading, then 24% on second reading, and only 9% concluded through conciliation. Decisions under OLP based on Qualified Majority Voting. Therefore, unanimity is not a requirement. Each of MS has votes depending on population size. As new rule applied on 2014, double majority rule required majority of 55% of MS (15/28) if made by Commission or High Rep. when it’s made by others, 72% majority is needed. Regardless of who made it, 65% majority of overall EU population is a requirement.