Breaking down the Brexit border problem

The UK government has been heavily criticised for planning to override part of the Brexit Withdrawal Agreement that it reached with the EU.

It acknowledges that doing so would break international law.

At the heart of the latest Brexit escalation is the thorny issue of where customs checks should be between the UK and the EU.

The BBC's Ros Atkins explains the issue, and it's about much more then where the forms get filled in.