With the Percival Gull already making a name for itself as a racer, over several months in 1933–1934, Capt. Edgar W. Percival designed and built a single-seat racer derivative initially named the E1 'Mew Gull'. This was developed into the E2, E2H and the E3H variants between 1934 and 1938. The sometimes-used designation "P6" is incorrect; this retrospective tag was created after Percival left the company and long after the Mew Gulls were built, thus no Mew Gulls were ever built as "P6s". With the exception of the sole E3H, "G-AFAA" – which was built after the company moved to Luton, all of the Mew Gulls were built in the small factory at Gravesend. The E3H, whilst very strongly visually resembling the E2H, was in truth a totally new and different machine, with each element differing from its predecessor in some way. It was most certainly not a 'clipped-wing' version of the E2H as it has sometimes been described.