There is a closely related idiom, often in the form:
fall at the final hurdle
To fail to accomplish some task or goal at the very end of the
- Negotiations between the two warring countries fell at the final hurdle due to disagreements over cross-border taxation.
Farlex Dictionary of Idioms
But Collins lists the phrase the final hurdle itself as at least a strong collocation (obviously from the examples often used metaphorically, thus an idiom):
- The final hurdle of planning permission has just been cleared. [Times, Sunday Times]
And below are further similar examples:
- The final hurdle: preparation for the PhD viva examination
[Barbara Jack; NIH National Library of Medicine]
- We’re now approaching the final hurdle on the road to a privacy-first, cookieless industry.
[WARC; March 2022]
- Today, we have reached the final hurdle in the long-delayed patriation process.
[De Hansard archive; Cambridge Dictionary]
One contributor requires that the question
- 'Can you use "last stretch" to refer to one final exam? I think the last stretch is used to refer to several events upcoming, but not a single event.'
also be addressed. John Lawler has already done this in a 'comment'; I assume I'm agreeing with JL that because of lack of research shown, an 'answer' is not really appropriate. However, I'll add a referenced answer. Longman brings out the metaphorical usage well:
the home/final stretch
- a) the last part of a track before the end of a race
- b) the last part of an activity, trip, or process
As they enter the home stretch of the campaign, the president’s lead has grown.
'The last part of a process' seems to licence a punctive/punctual event (such as a typical exam). However, I've found no examples in dictionaries or the first few pages of raw Google searches for "final stretch" or "last stretch" (not as common) which definitely refer to a culminating short event, and most of them definitely don't, referring definitively to the run-up (eg
- It was an easy trip except for the last stretch, which took forever.)
I'd say that, as an easy alternative presents itself, it is better to restrict 'last stretch' to the path (non-punctive) metaphor.