  A popular formation scenario for giant elliptical galaxies proposes that they
might have formed from binary mergers of disk galaxies. Difficulties with the
scenario that emerged from earlier studies included providing the necessary
stellar mass and metallicity, maintaining the tight color-magnitude relation
and avoiding phase space limits. In this paper we revisit the issue and put
constraints on the binary disc merger scenario based on the stellar populations
of disc galaxies. We draw the following conclusions: Low redshift collisionless
or gaseous mergers of present day Milky Way like disc galaxies do not form
present day elliptical galaxies. Binary mergers of the progenitors of present
day Milky Way like disc galaxies can have evolved into intermediate mass
elliptical galaxies ($M < M_*$) if they have merged earlier than $\approx$ 3-4
Gyrs ago. Assuming that most present day disk galaxies formed in a similar way
to the Milky Way model presented here, more massive giant ellipticals in
general can not have formed from binary mergers of the progenitors of present
day disc galaxies. A major reason for these conclusions is that the mass in
metals of typical disk galaxy is approximately a factor of 4-8 smaller than the
mass in metals of a typical early-type galaxy and this ratio grows to larger
values with increasing redshift.
