The UK is lagging behind many other countries when it comes to 4G coverage, new figures have revealed.
According to the National Infrastructure Commission (NIC), Britain's existing 4G network comes 54th in the world in terms of coverage, behind the likes of Albania, Panama and Peru.
The NIC was particularly critical of coverage levels on trains and motorways, with head of the body Lord Adonis saying it is "frankly appalling".
Speaking to BBC Radio 4's Today programme, he has therefore insisted the rollout of the future 5G network must be dealt with much better to ensure there are fewer dead spots.
"The government has been putting more investment and obligation requirements on the mobile operators but we think that needs to be taken further," he commented.
"We particularly think there is a big problem with our road and rail networks. Up to 25 per cent of the time it is not possible to get a decent signal."
The conclusion of the report has been hailed by Ofcom, which said it agrees with the NIC's view that universal coverage needs to be delivered.
"Our rules mean that virtually all UK premises must receive a 4G signal by the end of next year, and we're also making more airwaves available to boost mobile broadband," a spokesperson commented.
"Last month, we challenged mobile operators to explore how to reach all remote areas and transport lines."
Ofcom added that "robust data" on 4G in the UK will be published shortly to help inform decisions on improving coverage.
The report comes shortly after Chancellor of the Exchequer Philip Hammond announced in his Autumn Statement that £400 million is to be put towards improving the UK's fibre broadband infrastructure, with a further £740 million used to develop 5G services and a scheme that enables local authorities to bid for fibre connectivity.
A Treasury spokeswoman responded to the NIC report by stressing it wants the UK to "become a world leader in 5G".
She said the government will consider the body's report carefully and respond in next year's Budget.