The National Trust has launched a new strategy to mark its 3.5 millionth member.

The Our Future – Join In scheme specifies the conservation charity’s ambitions to deepen relationships with its supporters and promote closer engagement with those who join, visit or care for the trust’s work.

Director general Fiona Reynolds said: “Our long-term strategy is focused on engaging ever more deeply with our supporters; helping people identify with the trust as a cause as much as a place to enjoy and visit.

“We’ll be reviving the vision of our founders and reminding people how much history and a connection with nature matter in today’s crowded, changing world.”

The membership database accounts for 6 per cent of England, Wales and Northern Ireland’s population, and has rocketed by half a million new members within the last five years alone.

Reynolds added: “The levels of support we receive are truly inspiring – 3.5m people back the trust as members; 49,000 people volunteer with us; our houses and gardens receive 13 million visitors and there are a further 100 million visits to our countryside properties each year. This is a big movement of people who care for nature and history.”

Photograph: Children at Hanbury Hall, courtesy of NTPL/David Levenson