Pittella welcomed the victory of left-wing parties in Greece. He added the renegotiation of Greece's debt should no longer be considered a taboo.

"The Greek people have clearly chosen to stop the austerity imposed on them by the Troika's diktats and ask the new government to bring in fair policies with more social justice," he said.

It is now time to invest in economic growth to reduce deficit and public debt. The will of the Greek people should be respected by all the EU institutions and member states alike, he said.

"The S&D Group is ready to co-operate fully with the new progressive government," he added.

Syed Kamall, the leader of the third largest group in the EP, the European Conservatives and Reformists (ECR), said: "As a democrat, I congratulate the new government on winning the election."

"However, the new Greek government will have to face up to the reality that being part of the euro means you cannot just change economic course without the agreement of other eurozone countries, " he said.

Kamall added that while the Greek people may have made their choice, he questioned whether the voters of Germany, Finland, the Netherlands and other eurozone countries would be prepared to fund Greece via fiscal transfers if the new government decides to "splash the cash."

"The room for manoeuvre in the eurozone is limited but I hope that an agreement can be found that makes both the voters of Greece, and voters of other eurozone states, feel that they are being listened to," he said.