This is out of the question.
'Fuori discussione' — FUO-ri di-scus-SIO-ne. Stress on 'FUO' and 'SIO'. Four syllables in 'discussione'.
Use when a point or proposal is so unacceptable that you won't even consider it — it's outside the bounds of what can be discussed. Strong and final.
'Fuori discussione' (out of discussion = out of the question) signals that something cannot even be the subject of debate. It's not a point in your argument — it's a boundary. Used for matters of principle, safety, or ethics that you will not negotiate.
Non è nemmeno in discussione.
It's not even up for discussion.
Even stronger — 'nemmeno' (not even) reinforces that the topic can't be raised
Non posso nemmeno considerarlo.
I can't even consider it.
Personal refusal — makes the boundary personal and principled
È un limite invalicabile.
It's an uncrossable limit.
'Invalicabile' (uncrossable) — legal/formal language for absolute limits
Setting clear limits in Italian negotiations is not considered aggressive — it's expected. 'Non negoziabile' (non-negotiable) signals the boundary of your position. Italian negotiators respect clear limits more than vague flexibility, which can be misread as weakness.