THE Prime Minister's press chief Alastair Campbell has taken up a challenge to improve his lungs and support a national charity by running a marathon.

Mr Campbell, Tony Blair's director of communications and strategy, has already been seen leaving 10 Downing Street for a run, dressed in a replica football kit of his beloved Burnley.

He is one of a number of high profile figures, including his boss' wife, Cherie Blair, MPs and celebrities to support the British Lung Foundation's (BLF) Breathe Easy Week.

The initiative, which runs until the weekend, is being marked today with the launch of thousands of red balloons from Crystal Palace FC's Selhurst Park ground.

Each balloon is tagged with a "O2" or oxygen challenge for members of the public.

Dame Helena Shovelton, chief executive of the BLF, said: "More than 150,000 people die from lung disease each year in the UK.

"On average, one person in every family will have a lung condition, some smoking-related such as chronic obstructive pulmonary disease (COPD) but many such as asthma, not linked to smoking at all.

"We all have a responsibility to improve the nation's lung health to help reduce the number of people whose lives are devastated by lung disease."

Many figures, including Mrs Blair and the Conservative MP for Maidstone and The Weald, Ann Widdecombe, have vowed to help people they know stop smoking.

London Mayor Ken Livingstone said he aims to improve air quality in the capital so visitors as well as workers and residents can breathe more easily.

Apart from Mr Campbell, one of the more extreme challenges being taken up is by Bob Russell, the Liberal Democrat MP for Colchester.

He aims to walk across England from the Irish Sea to the North Sea.