The group said Sunday it did not recognize the dissolution of parliament, where it was the largest party. It also rejected the military's right to issue an interim constitution and oversee the drafting of a new one. 

That pointed to a potential struggle over spheres of authority between Egypt's two strongest forces. The Brotherhood has campaigned on a platform of bringing Egypt closer to a form of Islamic rule, but the military's grip puts it in a position to block that. 

Instead any conflict would likely center on more basic questions of control -- if the Brotherhood pushes a fight. It has reached accommodations with the military in the past. 

Official final results are not due until Thursday, and Shafiq's campaign challenged the Brotherhood claim, which was based on the group's compilation of election officials' returns from nearly all polling centers nationwide.