Spain has blocked the contentious appointment of Luxembourg’s central bank governor, Yves Mersch, to a top post in the European Central Bank, intensifying a row over the lack of gender balance in the institution.

The Spanish veto means the allocation of a seat on the ECB executive board, vacant since May, will be decided by EU leaders at a summit in a fortnight.

The manoeuvre was seen in Brussels as a ploy to gain a bargaining chip in talks on Spain’s financial crisis, although Spanish prime minister Mariano Rajoy may not be able to prevent the leaders from appointing Mr Mersch at the summit.

The European Parliament has voted against Mr Mersch’s appointment on gender grounds but its opinion is not binding on euro zone governments, which control appointments to the ECB upper ranks.

All of the national central bank chiefs who form the ECB governing council are male and so too are all the members of its executive board.

After MEPs voted, the Brussels authorities sought to make the appointment by way of a fast-track procedure in which governments can take a unanimous decision without a meeting between ministers. This process ran aground yesterday when Spain, which had pushed its own candidate, said it would not support Mr Mersch.

European leaders gather in Brussels on November 22nd to agree a seven-year EU budget.

A qualified majority of leaders can appoint Mr Mersch in that forum, so Mr Rajoy would need support from others to block him definitively.

Spain considers it a basic right to have a seat on the ECB board alongside other big powers like Germany, France and Italy. Its male nominee, Antonio Sáinz de Vicuña, head of legal services in the ECB, proved unacceptable to other countries.

Luxembourg’s prime minister, Jean-Claude Juncker, then made his continuation as president of the euro zone finance ministers conditional on Mr Mersch’s nomination.