 He helped draw up the European policy in the Conservative manifesto for the 1983 general election.Standing down at the 1984 election, Warner co-authored a pamphlet that November calling for the United Kingdom to become a full member of the European Monetary System.He was Chairman of the Overseas Committee of the Confederation of British Industry from 1985 to 1988, and in 1991 published a book titled "Anglo-Japanese Financial Relations".