By Francesco Canepa FRANKFURT (Reuters) - The European Central Bank cannot provide emergency funding to banks on overly generous terms or against insufficient collateral, it said on Tuesday, spelling out strict terms for banks in Greece and elsewhere to obtain such funds. The ECB, which has been providing an Emergency Liquidity Assistance (ELA) lifeline to Greek banks, on Monday raised the discount on the collateral Greece must put up in return for the cash, keeping pressure on Prime Minister Alexis Tsipras hours ahead of a meeting with other euro zone leaders. In a document published on its website on Tuesday, the ECB spelt out instances in which ELA provision would conflict with its objectives, saying it could not be supplied by national central banks against insufficient collateral and on generous terms that invited "moral hazard".