Me and my partner have been together over two years we have a baby together and I have a son from a previous relationship. My partner James has always looked upon my son as his own and has been there since he was 6 months old. My sons dad doesn't have contact with him as I got fed up of doing all the running around, he never made the effort to come and see him I always took him there. Now because I don't bother neither does he. What I want to know is do I still need the biological fathers consent for my partner to adopt my son?
Regards
Jade x

Yes you would biological fathers consent

First you have not said what county you are from. This may make some issues. Also within the US, each state has its own rules somewhat.

But basically you will have to petition the court where the child custody work has been done (normally since they were the original court of record on your custody agreement) If the biological father agrees ( will get him out of the child support) then your spouse can make petition to the court for adoption.
( it is all done at about the same time)

But I did not hear the magic word spouse, I only heard the word partner, which in today's society can mean many things, so depending on the state if in the US a partner may or may not be allowed to adopt

If you are in the states most states would require that the birth father sign over his paternal rights so that the child may be adopted.

I am in the U.K. My ex used to be violent to me and is a very strong drug and drink user.

You may be able to prove that he is unfit as a father so that your "partner" can gain adoption status. I am in the US, so do not know UK laws but this may help. However, I am not a professional in this area, but it may be necessary for you and your partner to be married.

Unless the biological father is deceased or has unknown whereabouts, then yes, he must give his consent in orde for his son to be adopted by another man.