Collaboration is impossible- Britney spears

Britney Spears

Britney Spears

Britney Spears

for a surprise onstage guest appearance at Britney Spears ' "Circus" tour will have to remain content with just Brit - the pop star shot down rumors that Madonna would join her during an upcoming performance.

"Despite rumors otherwise, at the moment Britney has no plans to collaborate with anyone in the near future at any of her upcoming performances," Brit's camp said in a statement posted on her official Web site.