The Avro Lancaster II is a four-engine variable-sweep wing strategic bomber used by the Royal Air Force (RAF) and Royal Canadian Air Force (RCAF). It was first envisioned in the 1970s as a replacement for the V-Bomber forces of the British Empire and Canada. Designed by A. V. Roe & Co. (Avro), the Lancaster II entered service in 1986 with both countries as a nuclear bomber. Throughout its development, there were several attempts to cancel it.
The Lancaster II's strong resemblance to the Long Beach AF B-1/74 has led to accusations of espionage from the UAPR, which both the RAF and Avro have categorically denied.