The most common and most likely answer to this crossword clue is the 8 plus 7 letter word POISONED CHALICE
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More clues leading to the result POISONED CHALICE
- Problematic gift of cocaine polished off
- Gift having adverse consequences once policies had changed
- Constabulary admits flipping coin: heads for evil in disguise
- This is likely to cause trouble, his deacon unfortunately being arrested by constabulary
- Chained so uncomfortably in custody? This could have unfortunate consequences
- Threatening item is concealed, I hope
- Unwelcome gift made undrinkĀable coffee, hated from the start by girl
Buddy explains!

The straight part
We know that "This could have unfortunate consequences" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case this could have unfortunate consequences = poisoned chalice.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.