  The Red MSX Source (RMS) survey is a multi-wavelength program of follow-up
observations designed to distinguish between genuine massive young stellar
objects (MYSOs) and other embedded or dusty objects, such as ultra compact (UC)
HII regions, evolved stars and planetary nebulae (PNe). We have identified
nearly 2000 massive YSOs candidates by comparing the colours of MSX and 2MASS
point sources to those of known MYSOs. Unfortunately, there are several other
types of embedded or dust enshrouded objects that have similar colours as MYSOs
and contaminate our sample. Two sources of contamination are from UCHII regions
and PNe, both of which can be identified from the radio emission emitted by
their ionised nebulae. In order to identify UCHII regions and PNe that
contaminate our sample we have conducted high resolution radio continuum
observations at 3.6 and 6 cm of all southern MYSOs candidates ($235< l < 350$)
using the Australia Telescope Compact Array (ATCA). These observations have a
spatial resolution of $\sim$1--2\arcsec and typical image rms noise values of
$\sim$0.3 mJy -- sensitive enough to detect a B0.5 star at the far side of the
Galaxy. Of the 826 RMS sources observed we found 199 to be associated with
radio emission, $\sim$25% of the sample. More significant than those sources
associated with radio emission are the 627 RMS sources for which no radio
emission was detected as these sources are still potential MYSOs. The Galactic
distribution, morphologies and spectral indices of the radio sources associated
with the RMS sources are consistent with these sources being UCHII regions. In
addition to the 826 RMS sources observed we present observations of a further
190 fields. These observations were made towards MSX sources that passed cuts
in earlier versions of the survey, but were later excluded.
