Congratulations poured in from Angela Merkel's European partners after her election victory. French President Francois Hollande - who has at times been at odds with Merkel over her tough austerity policies for Europe - was the first leader to call her after poll estimates showed her with a clear win, one of his aides said. "She was sensitive to that and she saw that as a sign of the strength of the French-German relationship and the closeness between the two countries," said the source. During their phone call, the two leaders "expressed their willingness ... to continue their close co-operation to meet the challenges of the European project", the French presidency said in a statement. Hollande also invited Merkel to Paris once her government is formed. Meanwhile, British Prime Minister David Cameron used Twitter to send Merkel his best wishes on her victory. "Many congratulations to Angela Merkel. I'm looking forward to continuing to work closely with her," he wrote. Prime Minister Enrico Letta of recession-hit Italy, which is going through a painful austerity drive, called the result "brilliant" for Merkel and also pointed to its significance for the European Union. "If the first results confirm that the anti-euro party is not represented in parliament, then, it would be a good result for the European Union," said Letta, in what appeared to be a reference to Germany's upstart Alternative for Germany (AfD) party. AfD tried to tap into anger over German contributions to bailout packages for stricken euro-zone partners, but preliminary results suggested that it would fall just short of the 5 per cent hurdle to earn seats in parliament. European Union president Herman Van Rompuy expressed confidence that Merkel, at the helm of the bloc's biggest economy, would continue to work for a "prosperous Europe". "I am confident that Germany and its new government will continue its commitment and contribution to the construction of a peaceful and prosperous Europe at the service of all its citizens," he said in a statement.