Seems rather dodgy if you ask me. They're not apparently vetting against the TPS lists. I’ve swiftly binned the call and added them to my blocked contacts.

I've received yet another one of those dodgy calls regarding diesel emissions pretending to be from numbers linked to Manchester, London, and Liverpool, all supposedly run by TELNYX. Make sure to block these nuisances and give Ofcom a heads-up, along with a message to 7726!