Research by the charity has found some groups are particularly struggling. It found 18 to 34-year-olds are three times as likely to be behind on their broadband bill than older groups. Those with children under 18 are three times as likely to be behind as those in households without children.

Households on Universal Credit are nine times as likely to be behind on their broadband bill compared to those not on the benefit.

This comes at a time when people are more reliant on broadband to work and help their children with schoolwork, with UK adults spending an average of 22 hours online each week.

Citizens Advice is warning that broadband is an essential utility, and that mobile data is not a substitute. This is particularly true when it comes to things like filling in job applications or where families are using multiple devices to work from home and do schoolwork.

Ultimately, falling behind on bills can lead to broadband being disconnected. But the charity’s frontline advisers also see people who simply cannot afford broadband in the first place, or are cutting back elsewhere to keep their connection.

In December, the regulator Ofcom “strongly urged” all providers to consider offering cheaper broadband tariffs for those on a low income or who are struggling financially. Only two nationwide and two local providers currently offer these tariffs, usually for people on Universal Credit.

Citizens Advice is calling on Ofcom and the Department for Digital, Culture, Media and Sport to urgently ensure all providers offer low-cost broadband to people on low incomes.

Dame Clare Moriarty, chief executive of Citizens Advice, said: “Broadband is not a luxury, it’s an essential, like gas and electricity. Lack of broadband creates yet another hurdle in the hunt for jobs, helping children with their schoolwork, and being able to access help, information and fill in forms online. Those with a broadband connection can have a huge head start on those who don’t.

“Ofcom and the government must ensure everyone can afford their broadband, no matter which provider they are with. People shouldn’t be penalised simply because their provider isn’t one of the few firms that offers a cheaper tariff.”

Broadband deals for people on low incomes

Virgin Media’s Essentials broadband deal is for people facing financial difficulty and receiving Universal Credit. It has a speed of 15Mbps and a fixed price of £15 per month.

The plan doesn’t have a fixed-term contract length and Virgin Media says the price won’t change while Universal Credit payments are being received.

BT is launching a broadband deal for people on certain means-tested benefits later this month. It is also called Essentials and will also cost £15 a month. Customers on the deal will get 40Mbps fibre broadband and 700 call minutes each month.