Relative clause introduced by an adverb

Question

“Your employment at Chent will terminate directly we find a suitable replacement.” (John Brunner, Quicksand, 1967)

This sentence is said by a highly formal and stuffy character. I guess this use of “directly” where it would be more common to say or write “as soon as” is formal and dated. Did it used to be more common? Is it still occasionally used in very formal contexts nowadays? Are there other similar constructs (an adverb introducing a subordinate clause with no conjunction, not even an elided that or who)?

Answer 1

According to the Oxford English Dictionary, directly can be used colloquially as a conjunction:

colloq. as conj. As soon as, the moment after. (Elliptical for directly that, as, or when.)

The examples they give include:

1795 Montford Castle I. 88 Directly you refused [his] assistance, a judgement overtook you.

1827 R. H. Froude Remains (1838) I. 68, I quite forget all my scepticism directly I fancy myself the object of their perception.

There is some discussion of this conjunction here, which noted:

So this use of directly is a Britishism. Similar words are immediately and instantly. Not all adverbs function as conjunctions, however, and there was debate about how proper such a use is (Dickens used them, but dictionaries didn't like the construction--note that the OED still calls it colloquial). The book mentioned above also notes that it is possible that any adverb could become a conjunction, so future uses of adverbs cum new conjunctions could occur:

The book notes that once and directly were being adopted at time of writing. Only once seems to have taken hold ("I'll be with you once I do XYZ") while directly remained a mostly British usage.

On formality, the Cambridge Dictionaries Online note that the phrase is slightly formal or formal, depending on how the conjunction is used.