London is presented as a stable place where tradition and honor hold sway. There is a strict class structure, but all the classes seem to get along by and large.
Paris is the central place of the French Revolution and therefore, a hotbed of chaos and bloodshed. Even before the revolution, it is presented as a corrupt place, with the aristocrats mistreating the peasant populace, running over small children, abusing the poor, and even committing rape and murder without having to answer to the authorities for any of their monstrous behavior.
Miss Pross and Mr. Lorry are representative of the general London populace: straitlaced, dependable, and loyal. Madame Defarge represents the revolutionary Paris in her desire for vengeance and self-destructive craving to destroy anyone who gets in her way.
England is different to Revolutionary France in that the rule of law still prevails. In France, the Great Terror is in full swing, with thousands of unfortunate individuals hauled up before revolutionary tribunals, often on the flimsiest of charges. If they're found guilty, as most of them are, then they can look forward to being slung into a dark, dank prison cell or even worse, guillotined in front of a baying mob.
In England, it's different. Although the country is in the grip of fear and paranoia over events across the Channel, certain legal proprieties are still maintained. A prime example of this comes in the case of Charles Darnay. Darnay is on trial for sedition, a very serious offense which would well see him being executed. However, unlike the revolutionary tribunals, the defendant's fate isn't determined in advance; there's still a little matter of evidence to be considered first. And under the glare of minute legal examination, the evidence against Darnay simply doesn't stack up. For one thing, the eyewitnesses testifying for the prosecution can't be sure it was Charles they saw, as he bears such a staggering resemblance to Sydney Carton, a junior member of Charles's legal team. And so Charles Darnay is acquitted, something that would never have happened under similar circumstances in France.
The dichotomy of London and Paris is a central element of the setting of the novel. From the first paragraph, Dickens shows that the two are completely different in their rulers, people, and culture. This is symbolized in numerous instances.
London could be represented by Tellson’s Bank and Mr. Lorry’s attitude and personality of order, rules, and trustworthiness. In contrast, Paris is disordered and violent. When the emigrants from Paris arrive in London, they bring that chaos into the bank, causing trouble for Mr. Lorry.
The class system can also be seen in the vast gap between rich and poor in France. In London, however, the classes mix to a certain extent, such as Jerry Cruncher being part of the “family” of the Manettes. While there is obviously a class structure in England, the people in those classes interact more than those in France, where they are in conflict to the point of destruction.
The families represented in the story also symbolize the differences in the two cities. Charles Darnay and his uncle have a great deal of conflict and little love, as does France. In the Manette family, however, there is companionship and a great deal of love among the members of the household, including the servants and friends, which is how Dickens wants to portray London during the French Revolution.