What was the significance of the flight to Varennes?

On the night of the 20/21st June 1791, King Louis XVI attempted to flee in an event that was later named the flight to Varennes. His plans were shrouded in secrecy, but he probably intended to flee to Montmedy in Lorraine, where he hoped to gain the protection of the royalist military commander and negotiate the terms of the new constitution. His brother claimed his intention was to leave France and return with the backing of his brother-in-law Emperor Leopold II and the Austrian armies. Whatever his intention, however, he only reached Varennes. He was brought back to Paris in disgrace and to the numbing silence of the hostile crowds. His actions had destroyed his last vestiges of support and Parisians began to talk seriously about a republic.

The Assembly faced a dilemma, as the King hasd shown his unreliability and their constitutional monarchy proposition looked unworkable, whilst they feared the 'rule by mob' under a republic. On 16th July 1791, the assembly voted to temporarily suspend the authority of the King, which was followed by an intense debate over his faith. Members of the Cordeliers argued that he should be dethroned or put on trial, whilst the moderate Jacobins broke away to form the Feuillant Club. As the Cordeliers and Jacobins attracted more radical support, a stream of petitions were sent to the Assembly, demanding that the King be removed from power and put on trial. 

CONSEQUENCES:

For the King 

Louis was now more than ever a prisoner of the Revolution and was regarded as a traitor, both to the Revolution and to the people. It was increasingly difficult for him to be viewed as a credible, constitutional monarch when he clearly did not believe in it. Moreover, the discovery of his armoire de fer lettre worsened the situation, as it contained an explanation of Louis' flight and denunciation of the work of the constituent assembly. 

For the Assembly

The Assembly was embarrassed and announced that the King had been kidnapped, attempting to hide the truth of his flight in order to avoid riots in the streets of Paris.

For France and the Revolution

This began a great fear that France was to be invaded, and increased the liklihood of a civil war between monarchists and Revolutionaries. The clamour for a republic was louder than ever.