The most common and most likely answer to this crossword clue is the 4 plus 2 plus 3 plus 4 letter word DOWN TO THE WIRE
D
O
W
N
T
O
T
H
E
W
I
R
E
Buddy explains!
The straight part
We know that "approaching deadline" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case approaching deadline = down to the wire.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.