Portsmouth named one of UK's worst cities for 4G mobile coverage

Consumer group Which? and analyst OpenSignal measured access and download speed from 20 of the country’s biggest cities by taking data measurements from more than 30,000 mobile phone users.

The report found Portsmouth and Southampton are in the bottom five cities for access to 4G , with 69.6 per cent availability.

Which? has called on Ofcom to keep pressure on mobile operators to ensure mobile phone service is available everywhere in the country.

The new figures, out today, show the average overall 4G availability across the UK is 65 per cent - meaning mobile users can only access 4G two thirds of the time.

More than 500 million data readings were taken from phones to produce the report.

Alex Neill, managing director of home products and services for Which? said: ‘These latest findings underline the need for Ofcom to keep the pressure on mobile operators, so that every part of the country gets a decent service on their mobile phone.

‘Our mobile phone is central to how we live our lives and that is why it is so frustrating when we can’t access emails or browse the internet on the go.’

OpenSignal chief executive Brendan Gill said: ‘The mobile data experience isn’t the same in every city for UK consumers.’