Sale of the body is immoral
By selling their bodies, sex workers are losing part of themselves.
The majority of sex workers are women,  and most rhetoric rests on the assumption that the sex workers being discussed are women, while the buyers are men. The majority of sex workers suffer from violence while working in their lifetimes. 
Violence is innately linked to prostitution, to the point that prostitution itself is a form of violence against women. Any state sanctioning of prostitution is essentially the state sanctioning of violence against women. As Bindel states, "prostitution [is] a form of violence in a neoliberal world in which human flesh has come to be viewed as a commodity, like a burger." The sex industry continually meets the desires of the customers. Sex workers are generally hired to represent or play out some sort of fantasy for the client. Transactional sex is often violent and abusive to fulfil base desires that may not otherwise be considered acceptable. The sex worker is simply an object or an outlet for the worst of client's sexual urges, pressured to conform to whatever the client demands. Sex workers are often the victims of abuse or murder. The death rate of sex workers is more than 40 times that of the general population, and the majority of sex workers in a five-country report were found to have suffered from physical, emotional and sexual violence over the course of their careers. Prostitution inherently dehumanises the sex worker and makes them an object that it is acceptable to impart violence upon. By making the sale of a woman's body acceptable, it makes the person expendable, and sanctions their being on the receiving end of violence. Under decriminalisation, violence against sex workers would become even worse than it is under criminalisation. As supply of prostitutes increases, prices will be driven down and sex workers will have to 'undercut' competition by accepting harmful sexual acts and violence. If prostitution is decriminalised, clients no longer have to fear the law and can treat sex workers however they wish.
There is no reason to state that prostitution itself is inherently a form of violence against women. The complex relationship between prostitution and violence is a reflection of a misogynistic society in which violence against women permeates every corner, rather than being specific to the act of prostitution itself. If we are concerned about the violent or misogynistic fantasies that clients are pressuring sex workers to carry out, we should evaluate where these come from. The fantasies precede the client visiting the sex worker. Therefore, to tackle the root of this problem we need to evaluate where these fantasies are coming from and the way in which women are sexualised in a demeaning and violent way throughout society. Sex worker collectives have repeatedly called for decriminalisation in order to reduce violence against themselves. The criminalisation of prostitution perpetuates violence against women by making sex workers unable to report violence through fear of prosecution. Women are unlikely to report violence against them at the hands of customers for this reason, and customers know this, creating an environment where sex workers are essentially at the mercy of their clients. Additionally, under a system of criminalisation many sex workers suffer violence at the hands of police when reporting violence. Sex workers do not have fair and equal protection to legal protection, as they are treated as criminals instead of being protected. As Goodyear and Cusick state, "Governments and health and social services have a duty of care without discrimination", and sex workers under criminalisation are being failed in this regard. By criminalising prostitution, rather than offering the victims of violence the opportunity to get help, governments are trapping victims and increasing their vulnerability. Under decriminalisation, on the other hand, sex workers are 70 per cent more likely to report violence at the hands of clients to police.
[P1] Violence against sex workers is innate to prostitution. [P2] Therefore, to decriminalise prostitution is to legalise violence against women.
[Rejecting P2] Criminalising prostitution makes prostitutes more vulnerable to violence.