One of the main architects of the single European currency, Jacques Delors, has said the eurozone was flawed from the beginning.
He told Britain's Daily Telegraph that the lack of central powers to co-ordinate economic policies allowed some members to run up unsustainable debt.
As head of the European Commission from 1985 to 1995, he played a key role in the process that launched the euro.
The comments come amid growing doubts over the viability of the eurozone.
In his interview with the Daily Telegraph, Mr Delors says the debt crisis stems not from the idea of a single currency itself, but from "a fault in execution" by political leaders who oversaw its launch.
He says they turned a blind eye to the fundamental weaknesses and imbalances of member states' economies.
"The finance ministers did not want to see anything disagreeable which they would be forced to deal with," the 86-year-old Frenchman says.
Mr Delors insists that all European countries must share the blame for the debt crisis - which has led to fears for the survival of the euro.
"Everyone must examine their consciences," he says.
'Too little, too late'
Commenting on those - like the British - who objected to euro membership by saying the currency could not work without a state, Mr Delors said: "They had a point."
The reaction of the current generation of EU leaders, he added, has been "too little, too late".
In particular Mr Delors identified "a combination of the stubbornness of the Germanic idea of monetary control, and the absence of a clear vision from all the other countries".
The BBC's Chris Morris in Brussels says the comments come ahead of a critical week for the eurozone.
On Friday, German Chancellor Angela Merkel said Europe was working towards setting up a "fiscal union", in an effort to impose budget discipline by members.
She and French President Nicolas Sarkozy have called for EU treaty changes.
The two are to meet on Monday, to agree on joint proposals to be put to a meeting of European leaders next week.