poisoned chalice
noun [ S ] uk/ˌpɔɪ.zənd ˈtʃæl.ɪs/ us/ˌpɔɪ.zənd ˈtʃæl.ɪs/
金杯毒酒;看似诱人实则有害的东西
something that seems very good when it is first received, but in fact does great harm to the person who receives it
The leadership of the party turned out to be a poisoned chalice. 该党的领导职位是个乍看起来诱人但实则害人的位置。