Final answer:
The nobility and clergy were typically against monarchs' centralizing efforts, as they feared losing their traditional power and privileges.
Step-by-step explanation:
The groups that were always against the centralizing efforts of the monarchs were nobility and clergy. These two groups had traditional power and privileges that they feared would be diminished by a centralized monarchy. The nobility, in particular, faced a shift in wealth generation from land to commerce and industry, which they initially disdained. The clergy and certain segments of nobility were also sometimes wary of monarchy's attempts to limit the power of the church. On the other hand, commoners, especially educated merchants and large landowners, often supported the idea of a British-style parliament as a check on the King's power. Artisans, shopkeepers, and small landowners shared an interest in reforms that would grant them more rights, including the right to vote.