A three-year programme aimed at generating more than €300bn (£237bn) for huge infrastructure projects across the European Union is to be launched by the EU executive with the aim of kickstarting growth, combating unemployment and addressing the lack of investment in Europe.

The InvestEU programme is to be announced at the European parliament in Strasbourg on Wednesday by the new and embattled head of the European commission, Jean-Claude Juncker, in what amounts to the first flagship policy of the new EU regime.

While Brussels and European capitals are vesting much hope in the investment instruments, there is also scepticism over whether the modest amount of seed capital being allotted to the programme can be leveraged on the financial markets into the ambitious figure of €300bn.

Officials who have been working on the policy for several months argue that they have learned the lessons of past failures, that the new initiative will take much bigger risks and that the current rock-bottom interest rates make the time ripe for attracting private investment on a large scale.

“There’s a lot liquidity on the markets, but investment is very low because there is a lot of uncertainty,” said a senior commission official. “We are going to remove that uncertainty and target riskier investment.”

The investment scheme has also attracted criticism, particularly from France, because it entails no new public money. Instead it represents a reshuffling of funds from the EU budget and the European Investment Bank (EIB), the Luxembourg-based EU vehicle for longer-term investment.

The fiscal hawks in Berlin who are preoccupied with producing Germany’s first balanced budget in almost half a century by next year have insisted that the Juncker plan not involve any more debt in the EU, while Britain has emphasised that the scheme must not lead to an increase in the EU budget.

France, by contrast, has been arguing that the basic fund should amount to up to €80bn in new EU money.

The seed capital, comprising public money put up by the EU, is believed to amount to about €20bn. These funds are the reallocated funds from the EU budget and the EIB and have caused critics to mutter about old wine in new bottles.

Since the financial crisis erupted in 2008 and the EU debt and currency emergencies in 2010, investment in Europe has slumped and remains at about a quarter below pre-crisis levels. Officials involved in drafting the programme insist they are being conservative in assessing the headline €300bn figure.

Jyrki Katainen, the former Finnish prime minister who is a new commission vice-president, is to tour global financial capitals to sell the programme and try to attract private investment in transnational transport, broadband, and energy infrastructure projects.

The seed capital will also be used to insure private investors and to weather potential early losses. While the plan is aimed at the next three years, officials say it could run much longer and be expanded to incorporate national investment schemes in the 28 member states.

The key role in the ambitious plan falls to the EIB, with Berlin insisting – and Brussels concurring – that no moves should be made that could imperil the bank’s triple‑A credit rating.

“Effectively we’re building a new EIB within the EIB,” said the senior official. “This is a different instrument taking bigger risks, but it will attract private money. The private sector comes in mainly at the level of individual projects.”

Reports have suggested that the aim was to attract up to €50bn in private money to be included in the initial seed capital fund to provide guarantees to other investors and offset potential first losses and provide insurance. However, people involved in drafting the programme denied this was the case.

Earlier suggestions that the EU could draw on its stability fund or eurozone bailout money were scuppered, mainly by German objections. The plans to kickstart an investment bonanza are the new European commission’s proposed answer to deal with the after-effects of the financial crisis, to re-balance years of German-led austerity, to try to redress the prospects of minimal growth, deflation, stagnation, and stubbornly high unemployment.

Following the unveiling of the scheme in Strasbourg on Wednesday, there will be plenty of turf battles before an EU summit of national leaders can sign off on the programme next month and before the investment vehicle can be turned into EU law early next year.