A new online train ticket retailer backed by the UK government is to be created, the Department for Transport (DfT) has announced, with the aim of simplifying the process of buying tickets from different rail operators.

However, the service will only be available once Great British Railways (GBR) has been established, which is not expected to take place until late 2026 at the earliest.

The DfT said in a notice that the online retail service would bring together individual train operators’ ticket websites and would “work alongside a thriving private sector retail market, where all rail retailers can compete in an open and fair manner”.

Private sector ticket retailers, including companies such as Trainline, RailEurope and TrainPal, will “continue to play a key role in driving growth through innovation and investment and encouraging more people to choose rail”, the DfT added.

Online train ticket sellers have previously been warned by the rail regulator, the Office of Rail and Road, to be more upfront about extra charges. It highlighted concerns about “drip pricing”, in which consumers are shown an initial price before add-ons such as booking fees are revealed later.

Exact plans for how GBR’s online retail service will work and how to ensure a fair and competitive market will be developed over time, the DfT said, confirming it would work on the project with industry and the private sector.

The decision revives an initial proposal for a new website and app to sell train tickets that was first announced in May 2021 by the Conservative government, under the then transport secretary, Grant Shapps.

However, the DfT said several months later it was “not pursuing” plans for a new retailer, highlighting the “important role” of the private sector.

Shares in Trainline, a big online train ticket retailer with 18 million customers, fell by almost 7% on Wednesday morning. The value of the company also took a knock when Shapps first shared his proposals in 2021, when they plunged by 23% in one day.

Jody Ford, the chief executive of Trainline, said the company welcomed the government’s “unequivocal commitment to a competitive retail market, underpinned by a level playing field, and recognition of the value and innovation that brings to rail users”.

The Labour government announced early steps to renationalise the railways in the king’s speech shortly after taking power last summer, including the railways bill, which will establish GBR. The body is intended to simplify the rail system, and will mean that track and trains are managed by the same organisation.

The DfT said on Wednesday that GBR would “deliver on the government’s commitment to simplify the complex web of fares and tickets that currently exist across the network, including by allowing passengers to buy tickets both online and offline”.