Complex sentence: The smallest component of the opposition were the Radicals, who were a largely middle class group of reformers, which despite philosophical differences with the more aristocratic Whigs usually ended up voting with them in Parliament.
Split into simpler sentences: The smallest component of the opposition were the Radicals, who were a largely middle class group of reformers. They had philosophical differences with the more aristocratic Whigs, but usually ended up voting with them in Parliament.