Newport docks' M4 relief road problem - in 60 seconds

The owners of Newport docks are lodging an official objection to the proposed route of the £1bn M4 relief road.

The so-called black route would cut across the site and Associated British Ports warned the height of the carriageway would be too low for the biggest ships to get in and out.

Newport, the UK's second biggest steel-handling port, supports 3,000 jobs.

The aim of the relief road is to speed up journeys for commuters and ease congestion.

BBC Wales' economics correspondent Sarah Dickins explains why ABP is concerned - in 60 seconds.