The European Commission has said it hopes to resolve, as soon as possible, the row over Finland's demand for collateral before it provides more cash for the next Greek bailout.

A spokesman for EU Economic and Monetary Affairs Commissioner Olli Rehn said this was important to 'restore confidence in the capacity of the eurozone to safeguard its financial stability'.

Finland's Finance Minister said its request for collateral, as a guarantee against a default by Athens, has to be met as the condition is contained in his coalition's new programme for government.

The move prompted the Dutch Government to demand similar assurances, but provoked criticism from other EU capitals that fear the Greek bailout could unravel.

Commissioner Rehn's spokesman, Amadeu Altafaj, said the euro group's technical committee was examining the issue.

While he declined to comment further, speculation suggests a compromise could be that Greece would put up property or shares in state companies as collateral, rather than cash.

Earlier, the Spanish government reached an agreement with the main opposition People's Party to establish limits on the public deficit and debt.

The constitutional amendment, which will not include specific deficit cap figures, will be accompanied by a law that will set a ceiling for Spain's structural deficit.

The move by Madrid follows calls by Germany and France for countries at the centre of the eurozone's debt crisis to set obligatory limits on deficits in order to regain the trust of investors.