"Without solidarity, the reasons for co-existence fall into the water," said European Parliament Speaker David Sassoli.
In an interview with the daily Corriere dellla Sera he said that "Europe can be stronger" provided that countries realize that they cannot get out of the current crisis by working each for themselves.
"I don't think some countries have noticed the magnitude of the disaster that is drawing us in and they don't understand the importance of the situation in their economy," Sassoli said.
Former European Commission President Jacques Delors also warned that "a lack of European solidarity poses a deadly threat to the European Union".
On the other hand, European Commissioner for Economy Paolo Gentiloni said that "the European project risks collapsing".
"It is clear that if economic differences between European countries increase and if the crisis escalates, it will be very difficult to maintain the European project," he said.
He also stressed that a solution must be found "inevitably through dialogue with Germany, without which no compromise will be reached".
Italian Prime Minister Giuseppe Conte said in an interview with Spanish newspaper Pais that this was not an economic crisis but a health crisis.
"This is a historic challenge for all of Europe," he said.
In Italy, 101,739 people have been infected with coronavirus and 11,591 have been killed until now.