By Environment Correspondent Alex Kirby

The environmental campaign Friends of the Earth (FoE) says air quality in the United Kingdom last year experienced the worst deterioration since modern records began.

FoE says it used government data and methods to calculate an air quality indicator for 1999. This shows, for key monitoring sites around the country, the average number of days on which pollution levels were above the government's own air quality standard.

The Deputy Prime Minister, John Prescott, who is also Environment Secretary, has called the standard "a key quality of life indicator".

FoE says the number of days last year on which air pollution exceeded health standards rose by 20% in urban areas and 53% in rural areas over 1998.

Monitoring sites

"In 1999, pollution levels were above health standards on average one day in eight at rural monitoring sites, and one day in 13 at urban monitoring sites. This is the biggest deterioration in air quality since records began in 1993."

The department of health has estimated that up to 24,000 people a year may die prematurely because of air pollution.

FoE says that Mr Prescott has refused to set a national air pollution reduction target, and that he intends to weaken the standard for dangerous small particles set in the national air quality strategy.

These particles, given off mainly by badly maintained diesel engines, are blamed for the deaths of more than 8,000 people a year.

FoE accuses the government of backing down on its election promises to cut road traffic levels.

Tony Bosworth, FoE's air pollution campaigner, said: "Parents, pensioners and asthma sufferers will be furious that the government is pandering to the roads lobby while they choke."

'Weather to blame'

But the environment department said in a statement that FoE had, "as usual, gone over the top with their claims".

"As FoE's own figures show, emissions from UK road transport are going down. 1999 was the second best year on record for urban air quality. The increase in days of high concentrations from 1998 was due to changes in weather conditions and pollution from mainland Europe.

"Focusing on a crude national road traffic reduction target is not the way to reduce congestion and pollution. This is the clear advice of the Commission for Integrated Transport - an independent body which includes environmental representatives."