Dickens satirized the Poor Law by describing the conditions in workhouses and especially those employed there.
The New Poor Law of 1834 might have been somewhat better than the previous version, but Dickens made it clear that there were still plenty of abuses.
Dickens describes the horrible conditions of the workhouse very satirically, commenting on how the poor inhabitants were fed so little by philosophers, and the governing board looked the other way because it saved them money.
Besides, the board made periodical pilgrimages to the farm, and always sent the beadle the day before, to say they were going. The children were neat and clean to behold, when they went; and what more would the people have! (ch 2)
The Beadle and the undertaker are a good example. The men even joke about how thin their charges become.
'The prices allowed by the board are very small, Mr. Bumble.'
'So are the coffins,' replied the beadle… (ch 4)
The fact that so many coffins are ordered by the workhouse, and the coffins are small because they are either for children or very thin people, is a joke between the two.
Even when Oliver is taken away to "a new scene of suffering" when he goes to work for the undertaker, there are still instances of satire of the poor's condition. Oliver is taken in by a "virtuous" gentleman who teaches his boys how to make pocket-handkerchiefs, by stealing them. The magistrate when Oliver is arrested is half-drunk and unaware of his situation. Dickens makes it very clear that the poor had no recourse.