When we want to express a strong negative opinion or suspicion of something or someone, we often use the phrase "least of all" in English. However, there are several alternative idioms that can convey a similar meaning and tone. For example, we could say "not in the slightest," "certainly not," "never for a moment," or "under no circumstances." Additionally, we might use more colorful expressions such as "not on your life," "no way, Jose," or "fat chance." Regardless of the specific phrasing, these idioms all communicate a sense of strong disbelief or rejection, emphasizing that whatever is being discussed is not even worthy of consideration.