Jelf wanted a church on his newly acquired estate where his Oxford seminarians could worship in the English language.

This led to a considerable controversy as there was an existing legal obligation to hold services in Welsh in all churches in Welsh-speaking areas.

His entry in the Dictionary of National Biography records that "faults of temper and manner rendered him unpopular", and much of his life was devoted to pursuing a large number of liturgical and ecclesiological controversies.

Jelf was determined that services in his church would be conducted in English, as few if any of his intended congregation of Oxford seminarians could speak Welsh.

[5] The Rector of Llanaber took Jelf to the Court of Arches, where Jelf lost his case, but his supporter, James Colquhoun Campbell, Bishop of Bangor, used his position in and influence over the House of Lords to secure the passing of the English Services in Wales Act of 1863,[6] which allowed the conduct of services in English in certain circumstances.

In addition to arguing for a sensitive approach to restoration and against the prevailing currents of the Gothic Revival, Petit, an experienced traveller, contended for the use of European sources.