Up until the deposition of the royal family in August 1792 and his own fall from grace, Barnave remained the most important advisor and supporter of the queen inside France. Marie Antoinette was ready to work with Barnave as long as he was ready to follow her orders, which Barnave did to a large extent and over a long period of time. Goaded by the queen, Barnave convinced Lafayette to use force against the radical elements of the French Revolution. As a result, tens of thousands of political opponents of Marie Antoinette were either killed, exiled or sent to prison. Rather than cooperating with Lafayette, Marie Antoinette refused to be helped by him and played a decisive role in defeating him in his aims to become the mayor of Paris in October 1791.[183]
Barnave and the moderates made up about 260 lawmakers in the new Legislative Assembly; the radicals numbered around 136, and the rest (around 350) were in the middle. At first, the majority was with Barnave, but the queen's policy led to the radicalization of the assembly and the moderates lost control of the legislative process. The moderate government collapsed in April 1792 and a radical ministry headed by the Girondins was formed. Worse than that, the assembly passed a series of laws concerning the Church, the aristocracy and the formation of new national guard units which were vetoed by the king on the orders of the queen. The radical Girondin government who was formed in April 1792 controlled the legislative assembly with 330 members, while Marie Antoinette and Barnave were not supported by more than 120 members.The two strongest members of that government were Jean Marie Roland, the husband of Madame Roland, who was minister of interior, and General Dumouriez, the minister of foreign affairs. Dumouriez sympathized with the royal couple and wanted to save them. However, he was rebuffed by the queen, who wanted to crush the Revolution by counting on the support of foreign powers.[184][185]
Marie Antoinette's actions in refusing to collaborate with the Girondin radical ministry who were in power between April and June 1792 led the Girondins to denounce the treason of the Austrian comity, a direct allusion to the Queen. After Madame Roland sent a letter to the King denouncing the Queen's role in these matters, the King sacked the Government on the order of Marie Antoinette, losing his majority in the Assembly. Dumouriez resigned and refused a post in any new government. At this point, most of the French people and political parties turned against the royal authority. Marie Antoinette even collaborated with Madame du Barry using the Duke of Brissac, the leader of the constitutional guard and the lover of Madame du Barry, as an intermediate to fund and prepare a counterrevolution in the War in the Vendee. This counterrevolution would interrupt in 1793, causing hundred of thousands of deaths and bring the Revolution to a quick end in 1799. In addition, Marie Antoinette pushed the king to refuse the new laws voted by the Legislative Assembly in 1792.[186] and continued her plots with the foreign powers by pushing them to issue the Declaration of Pillnitz in August 1791, which threatened invasion of France. This led in turn to a French declaration of war in April 1792 and the French Revolutionary War and the popular revolution of August 1792 which ended the monarchy.[187]