The cities of Madrid and Barcelona have moved to curb dangerous levels of atmospheric pollution sparked by a high-pressure system lodged over the Iberian peninsula, but ecologists have condemned the measures as inadequate.

Municipal authorities in the Spanish capital on Monday used overhead panels on the city’s ring road to advise drivers to take public transport “as a preventive measure” to avoid rising pollution levels, a spokesman said.

The government of the northeastern region of Catalonia, which had a long-standing plan to increase speed limits from 80 kph on some motorways entering Barcelona from Monday, postponed the measure to reduce the risk of pollution.

“There is a very strong anticyclone that moved in at the end of last week and the forecast is that it will remain at least until the weekend,” a spokesman for Barcelona’s city hall said. The high pressure system, which has brought sun and warm temperatures throughout almost all the country, “does not allow the pollutants to disperse” in the air, which means that pollution levels increase, he said.

The organisation Ecologists In Action accused Madrid authorities of “a grave dereliction of their duty to ensure that local people can breathe healthy air.

“Faced with this serious period of contamination, its actions are limited to recommending the use of public transport, something which is clearly ineffective as evidenced by the usual traffic jams that occurred today, and the continued high pollution levels at measuring stations.”

The municipal authority in Madrid, which is controlled by Spain’s conservative opposition Popular Party, came under fire last year for moving the measuring stations in a bid to post lower pollution levels.