Centre-left parties have named German Social Democrat Martin Schulz as their candidate for next head of the European Commission.
As they did so, they called for changes to the austerity policies brought in to tackle the eurozone crisis.
The Party of European Socialists – which groups the main centre-left parties – said the policies had led to unemployment and hardship.
“During the next five years, for every action we take in the EU we must be able to simply answer the question: how will this help to create jobs?” said Schulz.
“What more can we do to give a real chance for our children?”
Italy’s new prime minister Matteo Renzi also appeared at the conference in Rome – and repeated a pledge to keep finances under control, allowing it to push for new growth-orientated policies.
He also said that he wanted to ensure that the European Union is “a real social union, as much as it is an economical union.”
“Economic freedom cannot outweigh social rights,” he said.
Speaking from Rome, euronews correspondent Sandor Zsíros said: “At the end of his speech, Martin Schulz said that he’s confident that the European Socialists will win the elections in May. The latest polls show that the left has a small lead over the European People’s Party.”