Just when it must have seemed that the end of control was in sight, the threat of war revived fears of the excessive rent increases that led to the initial introduction of control in 1915, the Rent and Mortgage Interest Restrictions Act 1939 was introduced.
All dwellings not already subject to control, and with rateable values that did not exceed £100 in London, £90 in Scotland and £75 elsewhere were brought back into control.