The UK has warned Britons in Hong Kong that the territory has stopped recognising dual nationality and it might no longer be able to help citizens who also hold a local passport.

“If you have both British and Chinese nationality you may be treated as a Chinese citizen by local authorities, even if you enter Hong Kong on your British passport,” the UK’s Foreign, Commonwealth and Development Office said in an update to its travel advice. “If this is the case, the British consulate-general may not be able to offer you consular assistance.”

The shift in practice is in line with other efforts to bring the territory — which was promised a high degree of autonomy from the Chinese mainland for decades in the 1997 handover from the UK — closer to the rest of China.