[2] In 420 BC Manlius was elected as consular tribune together with Lucius Furius Medullinus, Aulus Sempronius Atratinus and either Lucius Quinctius Cincinnatus or his brother Titus Quinctius Poenus Cincinnatus (see their individual articles for discussion in regards to identification).
This was the first time Manlius held imperium but his colleagues were all experienced holders, having all been consulars previously.
For reasons unknown the election of these four consular tribunes were not held by the consuls of the previous year, but rather by a interrex, Lucius Papirius Mugillanus.
While the former consul, Sempronius, was convicted and forced to heavy fines by the joined efforts of the plebeian tribunes, Aulus Antistius, Sextus Pompilius and Marcus Canuleius.
The actions of Manlius and his colleagues during these trials are unknown, but the trial against Sempronius was partially fueled by the actions of his cousin, Manlius colleague, who had presided over the election of the Quaestors and there, in the opinion of the plebeian tribunes, misconducted.