If a natural father has not paid child support or gave no form of communication to the child for over three years can he be force by the courts to relinquish his rights?
He will refuse to give up his rights and to refuse to pay the $55,000+ in arrears. The step father, who has been in the child's life for the last eight years and my spouse for the last 3 years, wants to adopt the child. Taking place in TX. Harris county.

Generally, unless a parent is a danger to the child, there is no way to involuntarily terminate parental rights.

Have you taken him back to court over the arrears?

I moved this from the Adoption forum. Please pay more attention to posting instructions. There is a Read First note that directs legal questions to this forum.

As noted its very hard to get an involuntary TPR. Your best bet is to go after him hard for support and arrears, then offer to waive them if he relinquishes his rights.

Have you asked him if he would be more willing to sign for the adoption if you forgave the arrears ?