This briefing outlines the potential detrimental impact of the EU (Withdrawal) Bill 2017-19 on the UK’s efforts to prevent human trafficking and modern slavery, and the changes to the Bill that could prevent this.A significant proportion of workers’ rights in the UK come from the EU. The Withdrawal Bill leaves these rights vulnerable to being changed or weakened post-Brexit, without proper parliamentary scrutiny. The watering down of employment rights increases workers’ vulnerability to labour exploitation, including forced labour, slavery or servitude. FLEX supports Amendment 21 to the Bill, which would ensure that changes to employment standards that come from the EU can only be made if they do not reduce or weaken these rights and protections.