Why is 失礼 used here? And what function does に take?
First, I have no idea how the meaning „impoliteness“ should fit into this, with which jisho.org provides me http://jisho.org/search/shitsurei
Second, the “excuse” meaning was till now always connected to the verb suru „失礼します“.
Third, I don’t know how to meaningfully connect the phrase „失礼の内容“ to the verb „断る“ via the particle に. It makes little to no sense in my opinion should 断る take the meaning of „refuse“.
„To inform“ could work, but I can’t remember that I would ever have seen the particle に used in this way in such a context. Maybe „please inform (him/her) in the impolite details“ ?
I don’t know, I can’t beat sense into it.
I think I know what the sentence wants to tell me, but I can’t properly translate the sentence and therefore have no idea whether my vague interpretation is correct or not…