Brussels said the move, fiercely opposed by operators, would make journeys more seamless, helping passengers to find, compare and buy tickets in one go.

“Freedom of movement is one of Europe’s greatest achievements. Today, we are taking it a step further by making travel across all 27 member states simpler, smarter and more passenger friendly,” said the EU’s transport chief Apostolos Tzitzikostas.

The European Commission wants to improve rail connection across Europe to cut carbon emissions from air transport.

But the goal has long rubbed up against a fragmented network broken into national systems that critics say create hurdles and push up costs.

Passengers often have to buy tickets from different operators to patch together a multi-country trip.

Almost 400 million people travelled internationally by air within the bloc in 2024, compared to about 150 million who took cross-border train trips, according to EU data.

To change that, the commission proposed obliging rail operators to make their tickets available to all online platforms that want to sell them.

Undertakings that hold at least 50 percent of a national market would also have to display on their websites all services run in their country by competitors – and sell the related tickets if clients want them.

The Community of European Railways (CER) lobby group slammed the idea as an “unprecedented” regulatory overreach.

“I’m not aware of any case where somebody is obliged to sell the product of a competitor. Think about Lufthansa obliged to sell Ryanair” flights, CER head Alberto Mazzola told AFP.

Opposition from operators – often publicly run national champions – could hamper the plan’s chances to become law as it needs approval from EU member states.

Mazzola also argued that firms that invested in their ticketing platforms would have to open them to “free-riders”, and the requirement to hand over data would benefit US-operated booking giants, tilting negotiating power in their favour.

He added that cross-border rail travel accounted for only about 7 percent of train trips in Europe because high-speed infrastructure was not always there, and not because of ticketing issues.