Portugal is "extremely poorly connected" to Spain by train, with only one connection - Porto-Vigo - being made twice a day, highlights the environmental non-governmental organisation (NGO) Greenpeace.

Through the Porto-Vigo connection, in northwest Spain, it is possible to reach Madrid, with Greenpeace highlighting the fact that it is impossible to travel by train between the Iberian capitals on the same day.

To get from Porto to Madrid – in addition to the more than nine hours of travel over 420 kilometres – you need to make a stopover in Vigo.

In addition to the absence of a direct connection, the NGO points out that CP "does not sell tickets more than two months in advance and tickets for Spain have to be purchased from the Spanish rail operator", which further discourages the option for the train.

By plane, there are three low-cost operators with direct connections between Porto and the Spanish capital.

In Portugal, Greenpeace analyzed the Porto-Lisbon and Porto-Faro routes, comparing the options between the train and the plane, concluding that only on the former -- and due to the lack of connections with low-cost airlines -, the former is cheaper than the second and the journey takes just under three hours.

Between Lisbon and Porto, there are hourly train journeys and tickets cost between 15.5 and 25.25 euros, while the flight costs 37.46 euros.

On this route, the option for the plane involves the emission of 57 kilos of greenhouse gases per passenger and, if banned and replaced by the train, represents an 81% cut in emissions, highlights Greenpeace.

On the Porto-Faro route, there are three daily flights operated by a low-cost airline, with prices between 19.21 and 32.85 euros.

CP, on the other hand, has prices 70% higher and the journey takes almost six hours.

According to the study, long-haul journeys by train are, on average, twice as expensive as those by plane, with some routes costing up to 30 times as much as a ticket on a low-cost airline.

The NGO denounces that the railways are being "undermined" by competitive conditions favourable to airlines.