I appreciate it wasn't a 'large bomber' but there was also the Fleet Air Arm's Blackburn Skua although it was built to Air Ministry specifications, not the Admiralty's:
Originally Posted by Wikipedia
The Blackburn B-24 Skua was a carrier-based low-wing, two-seater, single-radial engine aircraft operated by the British Fleet Air Arm which combined the functions of a dive bomber and fighter. It was designed in the mid-1930s, and saw service in the early part of the Second World War...
Built to Air Ministry specification O.27/34, it was a low-wing monoplane of all-metal (duralumin) construction with a retractable undercarriage and enclosed cockpit. It was the Fleet Air Arm's first service monoplane, and was a radical departure for a service that was primarily equipped with open-cockpit biplanes such as the Fairey Swordfish...
Skuas are credited with the first confirmed "kill" by British aircraft during the Second World War: a Dornier Do 18 flying boat was downed over the North Sea on 26 September 1939 by three Skuas of 803 Naval Air Squadron, flying from the aircraft carrier HMS Ark Royal. On 10 April 1940, 16 Skuas of 800 and 803 NAS led by Lieutenant Commander William Lucy, flying from RNAS Hatston in Orkney Islands sank the German cruiser Königsberg in Bergen harbour during the German invasion of Norway. This was the first major warship ever to be sunk by dive bombing, indeed the first major warship ever sunk in war by air attack. Lucy later also became a fighter ace flying the Skua...
In the circumstances, these were considerable achievements.