"Danish prime minister Helle Thorning-Schmidt has told MEPs that Europe "stands on the edge of a political and economic catastrophe".
The former MEP was speaking in parliament as Denmark takes over the six-month rotating presidency of the EU.
Speaking on Wednesday, she said, "My greatest hope for the Danish presidency is for some plain speaking.
"It is sometimes said that the most courageous act in democratic politics is speaking 'truth unto power'.
"The presidency has begun well with its frank assessment of the damage a financial transaction tax would cause. I hope the presidency will continue in this vein and tell all leaders of the EU that the time has come to face the truth about the eurozone and the underlying European economic weakness."
Thorning-Schmidt, who was elected premier last year, was also scathing of the EU summit in Brussels in December which she called a "staggering missed opportunity".
She told the plenary in Strasbourg, "Instead of facing reality, the council has embarked on another round of introspective institutional navel-gazing."
She said the EU was "currently in the midst of not one but two great crises.
The eurozone may be the most immediate problem but we must not lose sight of the fact that Europe faces a fundamental challenge to its international economic position. We are losing competitiveness in the global market place.
"We are falling behind more dynamic regions of the world. We are allowing bureaucracy to stifle enterprise, and regulation to hamper innovation. As we work towards Europe 2020, we need a growth agenda which creates jobs, which encourages business."
The PM, whose country holds the presidency until the summer, said, "The EU must focus on stimulating economic reform and developing the single market.
"We therefore support some of the key priorities of the presidency."
MEP reaction to her address was swift, with European Conservatives and Reformists leader Martin Callanan MEP calling on Denmark to focus on economic competitiveness, growth and the single market.
He agreed with her comments about the summit, saying the meeting was "no springboard for recovery but more likely a prelude to disaster".
He said the agreement, over which UK prime minister David Cameron wielded the UK veto, "might solve the next eurozone crisis but not the current one".
"What is worse is that the European council diverted valuable political energy and resources away from facing the reality of the crisis. And in the aftermath, many have sought to make scapegoats of those who neither caused the problem nor have the power to implement a solution, maybe to distract attention from the summit's glaring failure," said Callanan.