Decriminalisation means sex worker specific support services will have their budgets cut and many will be closed
Sexual exploitation and criminality will exist within the sex work industry regardless of the legal status of prostitution, and sex work support services are essential to providing a barrier between sex workers and the social and legal consequences of their occupations. These services are frequently underfunded and stigmatized. Decriminalising sex work would call into question the necessity of these organisations. Theoretically, these organisations could lose their few supporters, who may believe their money should be directed towards organisations helping those who are unfairly criminalised. Already, Amnesty International is being taken to task over its support of decriminalising sex work in legislation, which proves that even well-intended services can be taken to task over the complex nature of prostitution and its legality.
The existence of those support services indicates that sex workers are not employed in a safe environment. Continuing to expose them to that environment by denying legality in the name of the organisations meant to protect them is, at the very least, deeply ironic.