  A difference in the electron mass at recombination from the measured value
today has been shown to relieve the Hubble tension. In this article we propose
a simple mechanism that would allow for such a mass difference. Similar in form
to the Higgs field, we consider a Yukawa coupling between the symmetron scalar
field and the electron. However, the symmetron vacuum expectation value depends
on the matter density of its environment which, in principle, would allow its
contribution towards the electron mass to differ between recombination and
today. We detail the coupling and discuss possible observables.
