The club failed to resign by March 31, the date by which clubs must inform the league that they intend to resign.
League chairman Glenn Youngman said:
“It’s really disappointing that Blyth resigned only a couple of weeks into the season.
“That decision has had a detrimental effect on the league. Following on from Team Northumbria’s resignation, It means that our first division only has 18 teams instead of 20.
“That affects spectators and players and also means that the 18 remaining clubs are facing a significant loss of revenue with fewer fixtures over the season.”