A bit clarification...
Vickers proposed at least two designs to the original Spec.B9/32.
The first in February 1933 was a high wing monoplane powered
by two Bristol Mercury VI engines.The aircraft had provision for wingfolding.
The horizontal tailplane was suported by struts. The undercariage retracted in
the backside of the engine gondola's and was partly enclosed.
The second dated from march 1934 was a midwing monoplane powered by R.R.Goshawk engines.
The u.c. was fully enclosed.This design bore no resemblence to to the later designs.
Both concepts would be covered by Vickers number 249.
Vickers type 271 was the constuctors answer to the already much revised and relaxed Spec B9/32.
For a few months in 1936 it was know as the 'Crecy' but in September this was changed in Wellington.
By the way, a designs study for a civil version of the Wellington was prepared in May 1939.
Sources

rofile Publications nr.125.Falkner & Sons.London.
Air Enthusiast nr.33 - United Kingdom.
and RAF Bomber Command and its Aircraft Vol.2 James Goulding&Philip Moyes.IanAllan U.K.1978.