It would depend on other income you may have, your age (re Tax allowances over 65 etc) but basically if you are already paying tax and with this additional amount it doesn't put you near the 40% tax bracket the tax would be 20% unless this amount is a capital gain or redundancy payment.
Hopefully you can find the info you need via the link posted by darkdog.
Sharing from experiences of dealing with debt
The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively.
Bob Marley. http://kallis3.blogs.iva.co.uk
I know this is a relatively old thread but I thought I'd share a really useful tool I use to do my own tax calculations with anyone interested.
Not sure whether you meant on a monthly salary before tax- I'll assume so
£2883 equates to a take-home salary of £2230 per month...