Although the UK Emergency Services main scheme radio coms are on Tetra Airwave which is due to be replaced by a 4g LTE network very soon the UK Dept for Communities and Local Gov have extended the tetra airwave contract for the fire service main scheme coms until 2019, but more likely 2020 and beyond.
Only the main scheme fire radios are Tetra, these are the ones mainly fitted in Fire Engines to keep in touch with control. The Main Firefighter handheld radios (also known as fireground radios) that all firemen wear and that are used at incidents will remain on the usual frequency of 457.0375.
Tetra was rolled out to the fire service in 2006 and had full coverage in 2010 and is known as “Firelink”. There has been a lot of criticism of the UK Gov who are accused of cost-cutting as a 4g LTE network may be much cheaper however it is far from ready and untested whereas the tetra network has proved to be reliable.
You can still listen to firefighters in the UK on their main handheld radios on frequency 457.03750. Depending on where you are in the UK they may be analogue or DMR Digital, either can be listened to an an average radio scanner. There are analogue and digital DMR modes available.
457.0375 is their main “primary” frequency. They also have other channels in their handheld radios, you can get the full frequency listings in The UK Scanning Directory
You can read more about the new extension to the Tetra contract for the UK Fire service at this article on computer weekly