By Piya Muqit In recent years, the impact of the Beijing-imposed national security law on freedom of expression, the rule of law and democracy itself has dominated coverage of Hong Kong. This is understandable. The city has been transformed by this controversial legislation as its autonomy from the mainland is eroded. Less discussed is how these changes have affected the city’s most marginalised communities – migrant workers, asylum-seekers and refugees, children – who have lost advocates, civil society groups and politicians willing to raise their concerns in the legislature, with the governm…