The NYT reports that the president of the German Bundesbank, Jens Weidmann, was worried that too much support was being provided.
He was also said to be concerned that the collateral provided by Popular Bank was worth less than the ECB's governing were told it was worth. And he said so forcefully.
Key voice
There are some of key bits of background to this story.
First, despite the creation of the European Central Bank, individual national central banks still exist and have some important functions.
In some circumstances they can provide emergency loans to banks that are struggling to raise the funds they need in the markets. It's called Emergency