A SMOG alert has been released as a cloud of Saharan dust threatens to cover Hampshire.

Air pollution is expected to reach high levels in “localised areas” of the UK and warnings have been issued to any people suffering chest complaints to avoid exercise, especially outdoors.

The dust cloud is due to settle today on the south coast and begin to spread north tomorrow.

Defra yesterday warned air pollution levels would rise to “moderate” today and could potentially affect much of England and Wales.

Levels are expected to stay “predominantly low” towards Scotland and Northern Ireland but forecasters warn that for the south and northern parts of England there is a high risk of air pollution.

The dust cloud is coming from the Sahara in the north of Africa and will affect parts of the country throughout the weekend as well.

The Defra Air Quality Index website has predicted that the situation would become worse tomorrow, it said: “With southeasterly winds from the continent dominating, the risk of moderate air pollution is likely to be widespread through this three-day period, with localised areas of high air pollution also possible.”

Health advice suggests adults and children with lung problems and adults with heart problems should reduce physical exertion particularly if they are outdoors.

Asthma sufferers should expect to have to use their inhalers more often, while older people are also warned to reduce physical exertion.

A Defra spokeswoman said: “Strong southeasterly winds blowing in air from the continent could lead to moderate levels of pollution tomorrow and over the weekend. Levels are expected to fall after the weekend.”