The Governing Council of the European Central Bank (ECB) has formally agreed to change its voting system after new member-states join the euro zone. The reform, which must be approved by EU finance ministers and the European Parliament, would introduce a rotation system once the number of euro zone countries exceeds 15. Under the changes, Ireland would vote at fewer than half of the meetings at which decisions are made on interest rates.

"The ECB recommendation provides for an adjustment of the voting modalities in the governing council which will become necessary to maintain its capacity for efficient and timely decision-making in an enlarged euro area," the ECB said in a statement.

Under the plan the governing council's six executive members would retain permanent voting rights. Euro zone member-states would be divided into three groups according to their economic weight and the size of their national financial sectors.