Nimrod MRA4 and Britain's maritime-patrol gap

Was the RAF trapped between Nimrod and having no maritime-patrol aircraft in the 2000s?

For a domestic or European replacement, largely yes. Completing MRA4 could have bridged the wait for P-8 and avoided a capability gap.

Britain's early-2000s options for a domestic or European maritime-patrol aircraft largely depended on upgrading Nimrod. A new alternative would have to come from the United States or Japan, while the existing airframes were ageing. The MRA4 rebuild had addressed the Comet family's problem of hand-built airframes whose spare parts fitted only one or two aircraft. With roughly 95 percent of the money already spent, completing MRA4 is judged preferable to discarding that investment. The proposed use was as an interim force until P-8 became available, avoiding the loss of maritime-patrol capability.