An attempt to construct a traditional Hubble diagram using objects other than supernovae, namely the infra-red (K-band) magnitudes of 3CR radio galaxies, assuming that these are giant ellipticals undergoing passive stellar evolution with respect to luminosity. Such an approach is degenerate with respect to choice of cosmological and evolutionary parameters. Uses the K-band Hubble diagram in combination with K-band differential number counts. The latter are similarly degenerate but in a different fashion; together the two data sets remove the degeneracy. MNRAS is a leading international journal, impact factor 5.057.