At the end of the 1936–37 season there were concerns about the league's viability. All five Essex clubs had left to join the newly established Essex County League, whilst Thetford had resigned after finishing bottom of the league, leaving only six remaining clubs. However, four new members (Colchester United reserves, Cromer, Newmarket Town and Norwich CEYMS) were recruited. The following season the league expanded to 13 clubs as two of the Essex clubs rejoined (the Essex County League had been a failure with only five members completing the season and was not continued).