Spanish hinterlands. Fearing vetoes from two of his tribunician colleagues, Trebonius had one of them locked in the senate house and prevented the other from entering the Forum with an obstructive mob. With the bill passed, they also made good on their promise to Caesar, putting forward legislation extending Caesar's term in Gaul for five more years. Pompey threw lavish games in September as part of his dedication of the Theatre of Pompey. News also came of Caesar's expedition beyond the Rhine to Britain; for these, the senate voted him twenty days of thanksgiving. The opposing tribunes attempted to obstruct recruitment for Crassus and Pompey's armies, but were unsuccessful. When Crassus left the city in November, escorted by Pompey, they announced bad omens, attempted to arrest him, and cursed him at the city's gate. Part of the justification against Crassus' campaign was in terms of immorality: "several in Cato's circle argued... the Parthians had given no justification for war". The elections for the year, however, went strongly against the allies. Unwilling to repeat their mob tactics due to their unpopularity, Pompey campaigned for one of his clients, Titus Ampius Balbus, but those efforts were in vain. The voters returned Lucius Domitius Ahenobarbus, denied victory by Pompey and Crassus' violence, and Appius Claudius Pulcher. Also elected was Cato for a praetorship; the next year, he would chair the court on extortion. Backlash The new consul Appius Claudius Pulcher seemed an ally, but as the political winds blew against the alliance, he quickly defected. Early in the year, he cooperated with them in securing the appointment of a Pompeian ally as one of Caesar's tribunes and obstructed Gabinius' prosecution (for the bribes received to induce his invasion of Egypt), but seeing Pompey's support for one Marcus Aemilius Scaurus rather than his brother for the consulship of 53 BC, he broke with Pompey and launched a prosecution against Scaurus. The alliance's opponents, led by Cato's coterie, also launched a broadside against their supporters in the courts: Gaius Porcius Cato, the tribune in 56 who had vetoed elections to delay them for Pompey and Crassus, was prosecuted but acquitted. He was then brought on new charges but again acquitted. Another tribune, Marcus Nonius Sufenas, who had helped Gaius Cato, was also tried. He was acquitted. Also prosecuted was a Pompeian tribune from 57 BC, who was also acquitted. In the case of Marcus Aemilius