Calls for a multibillion-pound cut in the UK’s overseas aid budget and closure of the Department for International Development (DfID) as a separate Whitehall entity are set out in a new Conservative vision for a post-Brexit “global Britain” backed by the former foreign secretary Boris Johnson.

Current definitions of aid spending would be broadened to include peacekeeping, and the BBC’s World Service would be expanded, as part of an effort to restore Britain’s ability to project soft and hard power.