  A systematic survey measuring the submillimetre continuum luminosity in radio
galaxies between redshifts z ~ 0.1 - 5 is currently in progress. The first
results from observations with the bolometer array SCUBA on the JCMT suggest a
trend of increasing submillimetre luminosity with redshift out to z ~ 4.
Assuming the continuum emission at 850um is dominated by thermal radiation from
dust heated by young, massive stars, the straightforward interpretation of
these data implies that the host galaxies of powerful radio sources, presumably
ellipticals or their progenitors, exhibit increased star formation activity
with increasing redshift. However a severe bias may distort the true picture
since only a subset of 30 galaxies have been observed, which represent the most
luminous radio sources (P_(151 MHz) > 10^27.5 W Hz^-1 sr^-1), whilst the
complete sample covers ~4 decades in radio power (10^25 - 10^29 W Hz^-1 sr^-1).
This on-going observational programme continues to improve coverage of the
radio power-redshift plane in an attempt to remove this potential bias towards
higher AGN activity and hence understand more fully the relationship between
high-z AGN, their level of starformation, and the evolutionary status of their
host galaxies.
