Who controlled British military-aircraft names

Were British aircraft names determined mainly by the RAF rather than by manufacturers?

Not in the 1920s: manufacturers still led naming to a significant degree, while RAF involvement increased during the 1930s without becoming absolute control.

No single rule covers the whole interwar period. Manufacturers retained considerable influence over names in the 1920s, which helps explain the distinctive sequence of early Hawker types. RAF involvement became stronger during the 1930s, although the service did not exercise as much control as later accounts sometimes imply. Procurement culture and naming practice changed over time instead of switching all at once.