Returning to Paris, Dumouriez encountered popular ovation, but he gained less sympathy from the revolutionary government. His old-fashioned methodical method of conducting war exposed him to the criticism of ardent Jacobins, and a defeat would have meant the end of his career. To the more radical elements in Paris, it became clear that Dumouriez was not a true patriot when he returned to Paris on 1 January 1793 and worked during the trial of Louis XVI to save him from execution. Dumouriez had also written a letter to the Convention scolding it for not supplying his army to his satisfaction and for the Decree of 15 December, which allowed the French armies to loot in the territory they had won. The Decree insured that any plan concerning Belgium would fail due to a lack of popular support among the Belgians. This letter became known as “Dumouriez’s declaration of war”. After a major defeat in the Battle of Neerwinden in March 1793, he made a desperate move to save himself from his radical enemies. Arresting the four deputy-commissioners of the National Convention who had been sent to inquire into his conduct (Camus, Bancal-des-Issarts, Quinette, and Lamarque) as well as the Minister of War, Pierre Riel de Beurnonville, he handed them over to the enemy, and then attempted to persuade his troops to march on Paris and overthrow the revolutionary government. The attempt failed, and Dumouriez, along with the duc de Chartres (afterwards King Louis Philippe) and his younger brother, the duc de Montpensier, fled into the Austrian camp. This blow left the Girondists vulnerable due to their association with Dumouriez.