Mehmed Ali's centralized Egypt rivaled Istanbul's provincial control. [causal]
Being an Ottoman governor himself, and realizing how serious the situation of the Empire had become in his time, the Pasha was sharing feelings with other nineteenth-century Ottoman reformers concerning the urgency of instituting an ambitious reform program in the Empire. The problem, however, lay in the fact that whereas the changes that these reformers were contemplating and which Mahmud II was spearheading meant, among other things, strengthening the central government's authority over that of the provinces, Mehmed Ali's reforms in Egypt meant exactly the opposite. For what Mehmed Ali had managed to accomplish was to create another center within the Empire that rivaled Istanbul in its ability to control neighboring provinces and, in effect, challenged its superiority as a leading political center in the Empire. And in that sense Mahmud II and Mehmed Ali were essentially rivals.
Khaled Fahmy, All the Pasha_s Men_ Mehmed…, loc. 225