  We present a field-theoretic renormalization group (RG) analysis of a single
flexible, screened polyelectrolyte chain (a Debye-H\"uckel chain) in a polar
solvent. We point out that the Debye-H\"uckel chain may be mapped onto a local
field theory which has the same fixed point as a generalised $n \to 1$ Potts
model. Systematic analysis of the field theory shows that the system is one
with two interplaying length-scales requiring the calculation of scaling
functions as well as exponents to fully describe its physical behaviour. To
illustrate this, we solve the RG equation and explicitly calculate the
exponents and the mean end-to-end length of the chain.
