The EU constitution, rejected by the populations of France and the Netherlands and quietly shelved before even being put to a vote in Britain, must be adopted by 2009, the German Chancellor said today.

Speaking to the European Parliament at the start of Germany's six-month presidency of the bloc, Angela Merkel told MEPs that the EU must find a way in the coming months for all 27 members to agree on a text or risk "historic failure".

Her statement raised immediate questions about how the constitution can be adapted for ratification in the eight countries yet to accept the document, which envisages widespread reform of the EU's bureaucratic machine. Britain, Poland and the Czech Republic have all promised their citizens a vote on the constitution but cancelled plans for their referenda after the defeats in France and the Netherlands last year.

"The reflection pause is over. By June, we must reach a decision on what to do with the constitution," Ms Merkel told MEPs in her first address to the European Parliament in Strasbourg. "It is in the interest of Europe to end this process successfully by the next European elections in 2009."

Resurrecting the EU constitution will be the centre-piece of an ambitious agenda under Germany's presidency of the EU, Ms Merkel said today, alongside reviving global trade talks and negotiating a collective "partnership" agreement with Russia.

The constitution will ease the bureaucratic confusion at the centre of the EU and properly integrate the 12 countries that have joined the bloc since 2004, Ms Merkel argued, bringing the chamber to a standing ovation when she promised that the document would create the post of an EU Foreign Minister, better able to represent the group on the world stage.

"A lumbering bureaucratic, divided Europe will not solve the challenges it faces, be they in foreign and security policy, climate and energy, European research, cutting red tape or in dealing with enlargement and with our neighbours," she said. "We must give a soul to Europe; we have to find Europe’s soul. Any failure could be a historic failure."

Ms Merkel had the support of Jose Manuel Barroso, the President of the European Commission, who said he looked forward to "a settlement to clear the clouds of doubt" over the constitution, but she met immediate resistance from MEPs concerned that governments would seek to abandon referenda previously promised to their voters.

"We need public debate, we need a convention, we need a vote," said Daniel Cohn-Bendit, co-president of the European Green group.

Neil Parish, a Conservative MEP, said Brussels was now going "full steam ahead to thrust the constitution upon us".

"If the leaders of the EU attempt to airbrush out the wishes of the French and Dutch voters, they risk destroying the very institutions they revere," he said.

With Tony Blair and Jacques Chirac, the French President, set to leave office later this year, Ms Merkel will be the most influential European politician in the coming months. Today she said she would urge the US to follow the EU's lead in adopting climate change legislation and promised a "resolute stand" in trade negotiations with the developing world.

But the most urgent issue for Europe is to bring some order to its relationship with Russia. The bloc's dependency on Moscow for oil and gas has made President Vladimir Putin a formidable negotiating partner, with a dispute between Russia and Poland over meat products currently holding up talking over a wider EU-Russia accord. Ms Merkel described Moscow's recent decision to cut off oil supplies to neighbouring Belarus because of an argument over energy prices as worrying.

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