Utilita Energy has filed for a judicial review into the end date for the installation of SMETS1 meters for pay as you go (PAYG) customers.
The energy supplier said it has “repeatedly urged” the Department for Business, Energy and Industrial Strategy (BEIS) to push the deadline back to at least 2020.
It claims it has been “left with no choice” and suggests SMETS2 meters could have a “negative impact” on vulnerable households if the network goes down.
BEIS is pushing ahead with its plans to deploy SMETS2 meters and said it will “vigorously defend” the judicial review claim.
The government extended the deadline for the installation of the first generation of smart meters by three months in January.
The original end date for SMETS1 of 13 July 2018 was pushed back to 5 October 2018.
Bill Bullen, chief executive of Utilita, said: “We have been left with no choice but to take this course of action – this is not a decision we have taken lightly.
“The smart meter rollout is designed to offer a better level of service for households. We believe abandoning SMETS1 meters at this time will have the reverse effect for millions of low income households that use PAYG.
“It’s been suggested SMETS2 meters are more advanced than SMETS1 meters – but this is simply not true. Indeed, for the PAYG market SMETS1 are secure, cost effective, interoperable and provide additional functionality not supported by SMETS2 meters.”
He added: “Our motivation is purely in the best interests of PAYG households – many of whom are among the most vulnerable in the country.
“It is indisputable that SMETS1 meters currently offers them a better level of service.”
Utilita said its SMETS1 meters have a keypad which allows PAYG customers to serve themselves if there are any difficulties and the network is down.
It claims SMETS2 is not designed for self-service and has the potential to put “millions of households at risk of going off supply”.
Bullen said: “We cannot rush this. We fully support the roll-out of smart meters, indeed with 90 per cent of our 650,000 customers already having them, we are more advanced than any other company – but it has to be at the right time for everyone, and this is clearly not the right time for SMETS2.
“There is still huge uncertainty regarding the full-scale deployment of SMETS2 meters which have not been properly tested for the PAYG market.”
The company highlighted there are only a few hundred SMETS2 meters in operation and none in PAYG.
A BEIS spokesperson, said: “Second generation smart meters, known as SMETS2, will enable all consumers to be able to use smart services when they switch energy supplier – enabling them to save money on their bills.
“That is why, after careful consideration of the impact on energy suppliers and consumers, we have set a deadline for energy suppliers to move over to deploying only SMETS2 meters.
“We will vigorously defend this judicial review claim.”
Utilita Energy took on thousands of Toto Energy customers on prepayment meters earlier this month. Toto Energy said it had made the decision to transfer the accounts for the “good” of customers.