The project, which would be co-financed by the European Union, was announced as Spain confronts a global energy shock caused by the US-Iran war, and as it positions itself to cope with climate change.

"The energy revolution can't be just for those who can change cars, put up solar panels on their roof or renovate their homes without subsidies," Spanish Prime Minister Pedro Sanchez said. "It needs to reach everyone."

For the plan to be adopted, Sanchez needs a majority of the parliament to back it, but his Socialist Party holds only a little over a third of the seats.

It calls for 4.7 billion euros to be set aside to make homes, public housing and neighbourhoods more energy efficient, and to promote communities sharing electricity and for solar panels to be installed on homes and in districts.

The other 4.3 billion euros would go to adapting transport, including in rural areas, and renovating fleets used by firms and independent workers.

A nearly free pass would also be given to people in low-income households and vulnerable groups.