The National Trust (NT) is offering jars of "fresh air" to city workers in London as part of its campaign to raise awareness of its 'open weekend' later this month.

NT's campaign posters will say that fresh air has been "captured" from rural and coastal locations such as Townend, Cumbria; Stourhead, Wiltshire, and Box Hill, Surrey, in a bid combat stress levels. Office workers across London are being invited to apply for a free jar of fresh as part of NT's Bonus Time project, which will see a range of trust-owned properties open for free between 20-21 March.

NT head of communications Andrew McLaughlin said: "With most of us living in an urban environment and having little time to escape to the great outdoors we thought it was about time the National Trust shared just a fraction of our copious amounts of fresh air with the nation." The NT is seeking to raise awareness of its new Bonus Time initiative, which was launched last month in a bid to encourage more people out of urban centres and into the countryside.