Its mandate as regulator is to ensure the European banking system is stable, rather than dabble in local matters. That means lenders would have to successfully argue that their capital buffers are under threat by a mere 3 billion euro levy that will be spread out across the sector. Up until now, lenders like Santander have been at pains to convince investors that they have ample capital to withstand a downturn. (By Aimee Donnellan)Follow @Breakingviews on TwitterRegister now for FREE unlimited access to Reuters.com Register(The author is a Reuters Breakingviews columnist. They do not reflect the views of Reuters News, which, under the Trust Principles, is committed to integrity, independence, and freedom from bias.

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