The Spanish daily newspaper El Pais wrote on Wednesday that Spanish Prime Minister's office has written a letter to European institutions. Spanish Prime Minister's office has asked for greater mobility of labour between EU member countries, increased fiscal union with a common budget and the issuance of common debt in the form of Eurobonds.

Madrid also asked the European Central Bank (ECB) to adopt a U.S. Federal Reserve-style mix of policy.

The Prime Minister's office and the ECB declined to comment.