More than 1.5m older and disabled Londoners are being left behind as a result of a digital-first approach to public transport that prioritises buying tickets on smartphone apps and the internet, it is claimed.

The warning comes from the consumer champion London TravelWatch, which argues these 'left behind Londoners' feel cut off from using public transport .

The group is calling for action by City Hall, Transport for London and train companies for action to ensure non-digital options, such as manned ticket offices and machines, remain available.

A survey for the group found one in six people in London say they are unable to buy a ticket as they can't use or don't have access to a smartphone or internet connection – the equivalent of more than 1.5 million Londoners.

A further one in five Londoners said that they have paid more for travel because they are not able to buy tickets online or by using mobile apps. The impact of this is particularly significant, given the current cost of living crisis, with rocketing utility bills and food prices.

The 'left behind Londoners' are typically over 55, more likely to be disabled and have a lower income.

Chief executive of London TravelWatch, Michael Roberts, said: "Many disabled and older Londoners have embraced new technologies in recent years, making it easier to get around the capital. But our research shows that a digital-first transport network disadvantages some of our most vulnerable citizens.

"A one-size-fits-all approach by transport providers does not work for a large section of London's population. That can't be right and it's why we're calling on decision makers to provide a system that is accessible, affordable and inclusive.

"We want transport operators to step up by pledging to keep prices the same across all platforms - nobody should be disadvantaged financially based on how accessible the technology is."

The survey found support from staff (22%) and information from ticket offices (21%) are the top two ways that digitally excluded and disadvantaged people access the help they need to get around the capital. The findings appear to be at odds with calls from ministers and rail companies to cut ticket offices in a modernising, cost-saving, measure.

Mr Roberts added: "We're also calling for staff to be more visible and available at stations to help those who need assistance.

"There should be training for staff and mentoring for people who want to learn how to use different ticket options. Transport operators should commit to consult and work with digitally excluded people and communities before any new technology is introduced."

The research report, launched today – Wednesday - at City Hall, calls for a number of key actions from decision makers and transport providers These include a demand that transport authorities and operators should maintain non-digital options to allow freedom of travel for digitally excluded and disadvantaged Londoners.

Chief executive of Transport for All, Caroline Stickland, said: "This report comes right on time for disabled Londoners as passengers are increasingly forced to rely on digital planning and ticketing. But if the barriers to these digital options are not addressed then disabled Londoners risk being excluded from transport completely.'

This report demonstrates the urgency with which these barriers need to be tackled, as well as the ongoing importance of staff support. A "modern" transport network must be one that is accessible for all.

Senior Campaigns Officer at Age UK London, John McGeachy, said: "The world is slowly waking up to the impact of digital disadvantage but there remains a real lack of understanding about how this links to aspects of people's lives such as the ability to access the transport network.

"Good public transport can make a huge difference to quality of life, especially for older Londoners, and when there are barriers to travel, we need to have an honest conversation about who is affected and how.

"It is fantastic that London Travelwatch is shining a light on transport and digital exclusion in the capital. The need to act has never been more important."