  We propose a generalization of the chiral Luttinger liquid theory to allow
for a unified description of quantum Hall edges with or without edge
reconstruction. Within this description edge reconstruction is found to be a
quantum phase transition in the universality class of one-dimensional dilute
Bose gas transition, whose critical behavior can be obtained exactly. At
principal filling factors $\nu=1/m$, we show the additional edge modes due to
edge reconstruction modifies the point contact tunneling exponent in the low
energy limit, by a small and non-universal amount.
