Sussex Jewish Representative Council -
Central point of contact for Jewish organisations mainly in Brighton & Hove
Helping Hands -
Practical and emotional support within the Jewish community in Sussex
Liberal Judaism - 
The national organisation to which ELJC is affiliated
LJY Netzer -
Liberal Judaism's youth movement
Board of Deputies -
National  cross-communal organisation representing interests of British Jews
World Union for Progressive Judaism -
International umbrella organisation for
Reform, Liberal, Progressive and Reconstructionist movements.

Map of Liberal (purple), Reform (blue) & Masorti (turquoise) Jewish Communities and Synagogues in the UK, with links to websites: 

View Liberal, Reform & Masorti Synagogues and Jewish Communities in the UK in a larger map