  We use data from the GAMA and GALEX surveys to demonstrate that the UV
upturn, an unexpected excess of ultraviolet flux from a hot stellar component,
seen in the spectra of many early-type galaxies, arises from processes internal
to individual galaxies with no measurable influence from the galaxies' larger
environment. We first define a clean sample of passive galaxies without a
significant contribution to their UV flux from low-level star formation. We
confirm that galaxies with the optical colours of red sequence galaxies often
have signs of residual star formation, which, without other information, would
prevent a convincing demonstration of the presence of UV upturns. However, by
including (NUV$-u$) and {\it WISE} (W2-W3) colours, and FUV data where it
exists, we can convincingly constrain samples to be composed of
non-star-forming objects. Using such a sample, we examine GALEX photometry of
low redshift GAMA galaxies in a range of low-density environments, from groups
to the general field, searching for UV upturns. We find a wide range of
(NUV$-r$) colours, entirely consistent with the range seen -- and attributed to
the UV upturn -- in low-redshift red sequence cluster galaxies. The range of
colours is independent of group multiplicity or velocity dispersion, with
isolated passive galaxies just as likely to have blue UV-to-optical colours,
implying significant upturn components, as those in richer groups and in the
previous data on clusters. This is supported by equivalent results for
(FUV$-r$) colours which are clear indicators of upturn components.
