Yes, during World War II, there were concerns within the Royal Air Force (RAF) about receiving too many *P-51 Mustangs* and not enough *Supermarine Spitfires*. This issue stemmed from the RAF's desire to maintain a balanced inventory of fighters suited to various operational needs, and the *Spitfire* was seen as the most capable British-designed fighter aircraft for many roles, especially in the defense of Britain and in Europe. The *P-51 Mustang*, while an excellent long-range escort fighter, was originally a U.S. design that was introduced to help protect Allied bombers deep in enemy territory.
The complaint primarily centered around the fact that while the *P-51 Mustang* was an outstanding high-altitude fighter with long range, the RAF had a pressing need for more *Spitfires* for short-range interception and tactical missions, particularly for use in European theaters where close air support and quick response times were critical. In particular, the RAF was concerned about the number of *P-51s* being allocated to the British, which left fewer resources for the more versatile *Spitfires*.
In response to these complaints, the United States did provide additional *Spitfires* to the RAF. Starting in 1942, the U.S. began sending *Spitfires* to Britain under the Lend-Lease program, and the RAF received several thousand of these aircraft during the war. The *Spitfire* remained a cornerstone of RAF air defense throughout the conflict, and it continued to be used in a variety of roles, including fighter-bomber and reconnaissance missions.
While the *P-51 Mustang* was highly regarded by both American and British forces, the RAF did indeed continue to prioritize the *Spitfire* for certain types of operations. Both aircraft played vital roles, and the U.S. and UK managed to cooperate on the distribution of these vital warplanes. Ultimately, the combination of *Spitfires* and *Mustangs* significantly contributed to the success of the Allies in the air.