European Commission President Jean-Claude Juncker has given details of a €315bn (£250bn; $393bn) investment plan to kick-start Europe's economy.At its heart is a new €21bn fund that would provide loans for infrastructure projects. Mr Juncker hopes most of the rest of the money will come from private backers.
Only €16bn of the original money would come from the European Union budget.
However, critics doubt it can attract so much private investment.
There was immediate scepticism from the European Trade Union Confederation (ETUC) whose General Secretary, Bernadette Segol, suggested the Commission was "relying on a financial miracle like the loaves and fishes".
She said she did not believe that €315bn could be raised from €21bn, a leverage factor of 15 which the ETUC argued was "almost certainly unrealistic".
The Commission believes it could create up to 1.3 million jobs with investment in broadband, energy networks and transport infrastructure, as well as education and research.
Analysis by BBC Europe editor Gavin Hewitt
This is the new Commission's big idea. It is the EU's New Deal.
To a large extent it will be judged by its success or failure.
The markets are currently awash with money. The big test is whether they will invest in Europe where the economy is stagnating and confidence is low.
"Europe needs a kick-start and today the Commission is providing the jump leads," Mr Juncker said as he detailed his ambitious five-year plan at the European Parliament in Strasbourg.
He said Europe had to face "the challenge of a generation" head-on, without a money-printing machine, and described his plan as the greatest effort in recent EU history to trigger additional investment without changing the rules.
The plan would take the burden off national governments, already facing big debts after the financial crisis. But they could contribute to the fund if they wished, and would be asked to come up with a list of projects with "high socio-economic returns" that would start between 2015 and 2017.
Illustrating the type of projects he has in mind, Mr Juncker said he had a vision of:
- Schoolchildren walking into a brand new classroom equipped with computers in the Greek city of Thessaloniki
- European hospitals saving lives with state of the art medical equipment
- French commuters charging electric cars on motorways in the same way as petrol stations are used now
- Households and companies becoming more energy efficient
Mr Juncker's speech came a day after Pope Francis addressed the same parliament, criticising an "elderly and haggard" Europe that had become less and less of a protagonist.
Initial reaction to Mr Juncker's plan came from Chancellor Angela Merkel, who told the German parliament that her government supported the package in principle, but it had to be clear to everyone where the projects were in the future.
The Commission president, who came to office at the start of November, said he could not promise how much investment would go to each country, but he argued that investment in one country could only be good for growth in another.
Structural reforms were necessary to modernise Europe's economy and fiscal responsibility was needed to restore confidence in public finance, but now investment had to be boosted as well, he said.
The start of the former Luxembourg prime minister's term as president has been overshadowed by his country's role in a tax break row.
Hundreds of multi-national firms were reportedly attracted to Luxembourg in legal tax avoidance schemes. Mr Juncker was prime minister at the time but denies wrongdoing.
Although a vote against him is due to take place at the European Parliament on Thursday, it is unlikely to attract widespread support.