I don't think it is Daviesia ulicifolia since that species tends to
produce dense racemes of flowers and has rather broad leaves. The
plant in the pic shows flowers in small clusters along the stem. I
grew something almost identical to that many years ago from seeds
collected in Oz by a friend's nephew who lived there. It took some
identifying (Australia has a bewildering number of native Fabaceae),
but it eventually turned out to be Pultenaea juniperina.

A somewhat straggling shrub with rather sharp, narrow leaves and
clusters of one, two or three flowers along the stems, arising from
each leaf axil. It grows in waste ground and dry heath type
vegetation in New South Wales, Victoria Tasmania and maybe S.
Australia. As a garden plant it's not the tidiest of things, but the
flowers when they appear are rather showy. Hard pruning of 1 year
growth immediately after flowering can keep it very much tidier, but
it resents older wood being cut. I couldn't persuade it to survive
winters outside in the Midlands, but I'm sure it would be very happy
in Devon and Cornwall. Academic really since I lost my plants many
moons ago. B&T World seeds sell it.

Photographs can be misleading, but I'd be prepared to put a moderately
large sum on it being a Pultenaea and just a slightly smaller amount
on it being juniperina.