Productivity in the UK's core cites is low by national and international standards and regional inequalities are continuing to increase, two new reports have revealed.

While second-tier cities in most other large developed countries have productivity levels that are as high as or higher than the national average, the gross value added (GVA) per worker in UK core cities was just 86% of the UK average in 2016, analysis by the Organisation for Economic Co-operation and Development (OECD) found.