Unions and socialist societies can affiliate to CLPs, to their mutual benefit. The organisations affiliated to Wimbledon CLP are:

• ASLEF
• CWU
• Fabian Society
• GMB K19 South West General; M27 LBM Branch; X03 CWU
• Merton Co-Operative Party
• Musicians’ Union
• Socialist Health Association
• TSSA
• UNISON
• UNITE LE/0019 Community; SW London; London & E.Region 790 (Legal); LS17
• USDAW H102 West Surrey