As default looms, Greece seeks to push back key July payments to ECB

On July 20, Greece has to redeem bonds worth 3.46 billion euros ($3.95 billion), currently held by the European Central Bank. Within a month of that, it faces another similar redemption of €3.19 billion (for more details on the timeline of Greece's debt repayments, click here.)

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Failure to pay the ECB would be disastrous in more than one way. In addition to the panic an actual default would cause by itself, it would make it impossible for the ECB to carry on lending to Greek banks against Greek government collateral through an emergency credit line. The banks would almost certainly collapse.