The CFSP is largely governed by unanimity. Exceptions to this general rule do exist, such as the appointment of the Secretary-General of the Council and High Representative for CFSP and the Special Representatives of the European Union, which may be based on a qualified majority. The endeavour to ensure unanimity and consensus nevertheless remains the main route for decision-making by the European partners in the CFSP domain. In practice, decisions are reached by consensus and voting is the exception. The 27th declaration appended to the TEU, on voting in the field of the common foreign and security policy, stipulates that «with regard to Council decisions requiring unanimity, Member States will, to the extent possible, avoid preventing a unanimous decision where a qualified major-ity exists in favour of that decision.»
Member States have the option of «constructive abstention» in this context. Under Article 23 of the Treaty on European Union, «When abstaining in a vote, any member of the Council may qualify its abstention by making a formal declaration [...]. In that case, it shall not be obliged to apply the decision, but shall accept that the decision commits the Union. In a spirit of mutual solidarity, the Member State concerned shall refrain from any action likely to conflict with or impede Union action based on that decision [...]». Although it has not been formally implemented, this mechanism has always been applied on a de facto basis, with Member States abstaining «constructively» when they do not oppose a decision.
The weighting defined in the Treaty of Nice in a Union of 27 Member States is as follows:
| Germany | 29 | Bulgaria | 10 |
| United Kingdom | 29 | Austria | 10 |
| France | 29 | Slovakia | 7 |
| Italy | 29 | Denmark | 7 |
| Spain | 27 | Finland | 7 |
| Poland | 27 | Ireland | 7 |
| Romania | 14 | Lithuania | 7 |
| Netherlands | 13 | Latvia | 4 |
| Greece | 12 | Slovenia | 4 |
| Czech Republic | 12 | Estonia | 4 |
| Belgium | 12 | Cyprus | 4 |
| Portugal | 12 | Luxembourg | 4 |
| Hungary | 12 | Malta | 3 |
| Sweden | 10 | Total | 345 |
In the case of the very few CFSP matters subject to qualified majority rules (since routine practice invariably prioritises consensus), Council acts must unite two-thirds of Member States and any of them may ask for the qualified majority vote to be verified as representing at least 62% of the total population of the European Union. If that condition is not met, the decision is not adopted. For the European Union of 27, the blocking minority will be 91 votes out of a total 345; the threshold for the qualified majority will be 255 votes representing at least two-thirds of Member States. The demographic verification clause remains in force.