Ros Atkins On... Four reasons why the relationship between the UK and China is strained

This week, Yang Tengbo was identified as the 50-year-old Chinese businessman and alleged spy banned from the UK.

It has triggered questions on an issue multiple UK governments have grappled with - the UK's relationship with China.

As the UK's chancellor prepares to visit China in the new year, the BBC's Analysis Editor Ros Atkins, looks at how relations between the two countries became so strained.