を控えて【をひかえて】

を控えて goes after a noun for an event – an exam, a wedding, an election, a move – and means it is coming up soon: "with X just ahead". The rest of the sentence says what people are doing or feeling because of it. It is formal, at home in the news and in writing.

In conversation you would say もうすぐきごう〜だから or きごう〜がちかい近いので.

を控えて or 前に

まえに前に only orders two events in time. を控えて says the event is close and matters, and that what you are doing now is because of it. A routine "before" does not take it.

控える, "cut back on"

The verb ひかえる控える on its own, with a food, a drink or an activity as its object, means "cut back on", "hold off". The difference is the noun: an upcoming event gives "ahead of", anything else gives "refrain from".

Usage notes

These go beyond を控えて joining two clauses.

Before a noun

To describe a noun, use をひかえた控えた.

を控え

Without て, を控え is the written form for reports and the news.