には賛成できない

can't agree with

→ に
phrase Rare #29,227
can't agree with Used to say that you cannot agree with or support someone or something. The に marks what you are agreeing with; できない means "cannot."
JA: その決定には賛成できない。
EN: I can't agree with that decision.

僕は君の考えには賛成できない

I can't agree with your opinion.

私はそんなプランには賛成できない

I can't agree with a plan like that.

彼の提案には賛成できない

I can't agree with his proposal.

私に関する限りでは彼の提案には賛成できない

As far as I'm concerned, I can't agree with his proposal.