A variation of this effect is for central banks, in the face of a high quality collateral shortage, to move away from sole reliance on reverse repos for injecting system liquidity. An obvious alternative instrument for this purpose, and one which we use extensively in New Zealand, is FX swaps.
Many questions about the role of the ECB during the crisis of March of 2013 still remain unanswered. Did the ECB play a constructive role or did it put pressure on the Cypriot government through the emergency liquidity assistance (ELA) mechanism? Under the rules of the Eurosystem, ELA can only be provided by national central banks to solvent banks.