Tourists look at a Madame Tussauds wax figure of Chancellor Angela Merkel in front Brandenburg Gate in Berlin to mark tomorrow's 60th birthday of the German leader July 16, 2014. [Photo/Agencies]

BERLIN - Angela Merkel, it seems, has had her fill of parties for now.

Just four days after joining Germany's jubilant soccer players in their dressing room to revel in their World Cup triumph, the chancellor is making sure she doesn't get carried away on her 60th birthday on Thursday.

It is hard to imagine a more low-key celebration for Merkel, named by Forbes magazine as the world's most powerful woman but still known as "Mutti", or Mummy, in her homeland where her no-nonsense attitude merely enhances her soaring popularity.

She will mark the birthday, which has set off a new debate about how long Germany's first female government leader will stay in office, at a rather serious event at her conservative party's headquarters in Berlin.

After a speech about "the time horizons of history" by the historian Juergen Osterhammel - Merkel's personal choice - up to sts will attend a reception with beer, wine and northern German fare including fish.

Nothing too fancy, said one official.

She may even see in her birthday in Brussels where European Union leaders meet late on Wednesday to haggle over how to carve up posts in the European Commission between member states - just the sort of challenge Merkel relishes.

After a tough start to the year, which saw her hobbling on crutches after a skiing accident, a crisis in Ukraine to deal with and her Social Democrat (SPD) coalition partners stealing the limelight on domestic policies, she looks as strong as ever.

A Forsa poll on Wednesday showed that even after 8-1/2 years as chancellor, some 59 percent of Germans would vote for Merkel in a head-to-head contest with her main rival, SPD chairman Sigmar Gabriel. Only 14 percent would vote for him.

An Infratest dimap poll on July 3 found that 71 percent of Germans were happy or very happy with her work. Germany's strong, well-managed economy within an otherwise troubled euro zone has helped her. Forsa chief Manfred Guellner said the World Cup victory could play in her favour as well.

"The chancellor stage-managed it skilfully as she went to Brazil for the first match and then for the final. The message was: I am paying it attention!" Her ratings are so high there is barely room for improvement, he said.