A cloud of toxic smog over Britain combined with air pollution blowing in from Europe has caused a health alert, and could be an obstacle to those hoping to get a glimpse of tomorrow’s rare solar eclipse.

The sun rises over trees at Bannockburn, Scotland, as Britain was placed on a health alert because a potentially dangerous cloud of air pollution is blowing over the country.

The sun rises over trees at Bannockburn, Scotland, as Britain was placed on a health alert because a potentially dangerous cloud of air pollution is blowing over the country. Image by Andrew Milligan/PA Wire

Still air and high pressure mean the pollution is building up, getting trapped in the atmosphere and causing problems.

The current cloud is being caused by a combination of home-grown smog, mixed with air pollution from the continent, The Department for Environment, Food and Rural Affairs (Defra), said.

Although it is expected to have mostly dissipated by tomorrow, it is thought that a haze could still remain, reducing visibility of the eclipse.

Experts have warned that the polluted air could cause fatal asthma attacks and have advised the elderly and those with health problems to be cautious.

(Press Association)