Hi Solitaire, it's nice to meet you!
Re- Lovatts Colossus 100 Cryptic competition
53A. Stability representative of justice (7)
I have 'balance' for my answer.
stability = balance
representative of justice = the 'Blind Lady Of Justice' holds a sword in one hand, and a 'balance' or 'scales' in the other.
That is the best that i can come up with- it drove me mad too!
Hope this helps you Solitaire, post again if you get stuck and I'll do my best to help you.
Regards, Butterfly