  Current models predict that binary interactions are a major ingredient for
the formation of bipolar planetary nebulae (PNe) and pre-planetary nebulae
(PPNe). Despite years of radial velocity (RV) monitoring, the paucity of known
binaries amongst the latter systems is insufficient to examine this
relationship in detail. In this paper, we report on the discovery of a long
period (P=2654$\pm$124 d) binary at the centre of the Galactic bipolar PPN,
IRAS 08005-2356 (V510 Pup) determined from long-term spectroscopic and
near-infrared time series data. The spectroscopic orbit is fit with an
eccentricity of 0.36$\pm$0.05 that is similar to other long period post-AGB
binaries. Time resolved H$\alpha$ profiles reveal high-velocity outflows (jets)
with de-projected velocities up to 231$_{-27}^{+31}$ km s$^{-1}$ seen at phases
when the luminous primary is behind the jet. The outflow traced by H$\alpha$ is
likely produced via accretion onto a main sequence companion for which we
calculate a mass of 0.63$\pm$0.13 M$_\odot$. This discovery is one of the first
cases of a confirmed binary PPN and demonstrates the importance of
high-resolution spectroscopic monitoring surveys on large telescopes in
revealing binarity among these systems.
