Trustees say the existing 60-year-old structure, unveiled on St Andrew’s Day 1965, is now in such serious decline that it can no longer be repaired.
The campaign has been supported by First Minister John Swinney, Scottish Secretary Douglas Alexander and Scotland’s pre-eminent historian, Professor Sir Tom Devine.
The announcement coincides with the 60th anniversary of the original memorial, created after a 1960s appeal led by the Earl of Wemyss and supported by civic leaders and the then Lord Lyon.
A letter to the Glasgow Herald in 1964 quoted the Rev T Ratcliffe Barnett, who said the “pleasant little village in East Lothian” ought to be “a place of pilgrimage for every loyal Scot”.
Both Mr Swinney and Mr Alexander, as well as the Moderator of the Church of Scotland, along with other faith leaders, will be attending a special St Andrew’s Day service in Athelstaneford this afternoon.
A large ceremonial Saltire will be carried by local children into the parish church for a service of dedication led by the local minister, the Rev Douglas Hamilton.
According to medieval chroniclers, the Saltire’s origins lie in a battle in 832 AD when a smaller Pictish and Scots force faced defeat against a Northumbrian army.
King Angus mac Fergus prayed for deliverance and saw a vision of a white diagonal cross in the sky, taken as a sign from St Andrew. His troops went on to win the battle, and the Saltire became the emblem of the emerging nation.
Dave Williamson, convenor of the Scottish Flag Trust, said a new monument was urgently needed to ensure that story is preserved.
“Scotland is indeed fortunate to be represented by the flag of our patron saint, the St Andrew’s Cross or Saltire, which serves as such a compelling and distinctive symbol for Scots everywhere, at home or abroad.
“Moreover, in which other country would one be able to point to an actual site where the national flag originated? It is this fact that makes Athelstaneford unique and worthy of special attention,” he said.
“The memorial in the parish churchyard has served us well for 60 years, but the passage of time has taken its toll on the concrete structure, and it needs to be replaced.
The Trust needs to raise over £300,000 to create a new memorial that will be a fitting testament to the story it represents, and that will inspire and educate future generations and the thousands of visitors who come each year.”
He added: “The Saltire has a special place in the heart of all Scots, including the diaspora, and the Trustees very much hope people, even in these difficult times, will rally to the cause and help preserve and promote the story of our national flag.”
The new monument has been designed by award-winning architects Simpson & Brown, with sculptor Tim Chalk and landscape architects Paul Hogarth and Company.
It will be built from dressed sandstone blocks and feature bronze relief panels depicting the opposing armies at the Battle of Athelstaneford.
The stonework will draw on the artistic style of Pictish carved stones, while the lettering will be inspired by illuminated manuscripts such as the Book of Kells.
A paved world map, rendered in coloured stone, will mark the locations of St Andrew and Saltire societies founded by Scots abroad. Each will be identified by a bronze disc bearing the Saltire motif, a deliberate reflection of the Trust’s aim to celebrate Scotland’s global connections.
There is cross-party support for the project to rebuild the monument.
A new public letter backing the project has been published today, signed by faith leaders, trade unions, cultural bodies and representatives of every party in Scotland.
Mr Swinney said: “St Andrew’s Day is a time to celebrate everything that makes the fabric of modern Scotland — our history and traditions, our values, our rich diversity of communities and cultures. As the place where the Saltire originated, Athelstaneford plays an important role in our nation’s identity.
“Scotland is world-famous for its warm welcome, and the Saltire is a proud representation of our inclusive values. I welcome the Scottish Flag Trust’s work to promote the Saltire as a symbol of peace, welcome and unity.”
Mr Alexander, who is also the MP for Lothian East, said the site held “a special place in Scotland’s story”.
“East Lothian itself is a community rich in history and pride, and that spirit will be at the heart of this year’s Saint Andrew’s Day gathering. I welcome the work of the Scottish Flag Trust and the local community in preserving this important site and in ensuring that the Saltire remains a symbol of welcome and belonging for all.”
Professor Sir Tom Devine, patron of the Trust, said: “It is essential that there be a fitting and lasting memorial to the origins of Scotland’s national flag. I therefore warmly commend this fundraising campaign to Scots both at home and abroad and indeed to all who have a love of Scotland.
“The launch of this appeal in 2025 is doubly important, as the apparent abuse of our national flag in the last few months to advance some sectional interests has been noted by the media. The Saltire is the historic symbol of collective unity for all Scots, whatever their origins may be.”
Donations can be made at saltire.scot.