Immigrationboards.com

I received my ILR (SET M) in February 2012. My wife and I are now separated (not legally). She has since expressed her intentions to commence divorce proceedings although no concrete actions have yet been taken. We have a child together.
My question is: can I still apply for citizenship since we are still technically married?

Cheers

Yes. For a BC application the Home Office still consider you to be married, even if legally separated.

Assuming you have completed 3 years of residence, you can apply now. Otherwise apply when you complete 3 years of residence. You would still need your wife's cooperation as you will need her documents (British passport or birth certificate) in order to apply. If you get divorced before you apply, then you can apply on your own merit after 5 years of residence.