Essay competitions

Can I ask which subject and if you're an early applicant?

No, I'm not an early applicant but I'm aiming for Russel Group. I'm interested in a range of social sciences, especially anthropology

I found this (deadline is October 31st): https://therai.org.uk/awards/prizes/curl-essay-prize/
Keep an eye out for details about this competitions as well (they said details would be published in October): https://www.gold.ac.uk/schools-and-colleges/young-writer-competitions/

'Competitions' are a waste of time - they are about as meaningful as a Brownie badge.
Universities just ignore them because they don't say any thing special about you, and dont mean you will be a 'better student' however you think you can measure that.
Do the extra reading, complete relevant Moocs etc, and identify a few topics that you can say something meaningful about to show that you now are thinking/studying beyond A level standard. That will tell any Uni far more about you, your motivation and subject interests, than 'I did a competition thing because everyone else does this'.
Good for all Unis :
Suggested Subject Resources | University of Oxford
super-curricular_suggestions.pdf (Cambridge)