Advice re British passport please

I came into the UK on a spouse visa in November 2009. I then got my ILR in April 2012. I am now separated from my husband of 25 years and want to apply for my British passport. Please can someone tell me when I would be eligible to apply. Many thanks.
PS I am originally South African.

You need to be granted British Citizenship before you can apply for a British passport. You could have applied for BC once you'd been granted ILR and completed 3 years of legal residence, as even though you're separated from your husband (assuming he is British), for British Citizenship you're still considered to be married.

Thank you yes he is British but would I have to supply his passport because I would rather not have anything to do with him

No problem. As long as you meet all the standard requirements, you can apply now in your own right.

Brilliant thanks very much