  We present a SCUBA submillimetre (450 & 850 micron) survey of the environment
of 105 IRAS point sources, selected from the Wood & Churchwell (1989a) and
Kurtz, Churchwell & Wood (1994) radio ultracompact (UC) HII region surveys. We
detected a total of 155 sub-mm clumps associated with the IRAS point sources
and identified three distinct types of object: ultracompact cm-wave sources
that are not associated with any sub-mm emission (sub-mm quiet objects), sub-mm
clumps that are associated with ultracompact cm-wave sources (radio-loud
clumps); and sub-mm clumps that are not associated with any known ultracompact
cm-wave sources (radio-quiet clumps). 90% of the sample of IRAS point sources
were found to be associated with strong sub-mm emission. We consider the sub-mm
colours, morphologies and distance-scaled fluxes of the sample of sub-mm clumps
and show that the sub-mm quiet objects are unlikely to represent embedded UC
HII regions unless they are located at large heliocentric distances. Many of
the 2.5 arcmin SCUBA fields contain more than one sub-mm clump, with an average
number of companions (the companion clump fraction) of 0.90. The clumps are
more strongly clustered than other candidate HMPOs and the mean clump surface
density exhibits a broken power-law distribution with a break at 3 pc. We
demonstrate that the sub-mm and cm-wave fluxes of the majority of radio-loud
clumps are in excellent agreement with the standard model of ultracompact HII
regions. We speculate on the nature of the radio-quiet sub-mm clumps and,
whilst we do not yet have sufficient data to conclude that they are in a pre-UC
HII region phase, we argue that their characteristics are suggestive of such a
stage.
