A 700-year-old bronze seal commissioned by Robert the Bruce and used on his official documents looks set to leave the UK unless a serious bidder comes forward today.

The extremely rare and valuable seal was prevented from leaving the country last December after being bought by a foreign buyer at auction for £151,250.

UK Culture Minister Ed Vaizey then agreed to an export bar, which ends today. He argued that the seal was “one of the few objects directly associated with Robert the Bruce’s reign” and its departure would “strip us of the opportunity to learn more about this exceptional figure”.

The Scottish Government said they would encourage any effort to “ensure this item stays within the UK”.

“The King Robert the Bruce of Scotland and Dunfermline Abbey Cokete Seal is of outstanding historical significance to Scotland and we welcome the temporary move to stop export of this important cultural object,” a spokeswoman said.

“The export bar allows for those who may wish to purchase this object adequate time to raise the required funds. The Scottish Government encourages any effort to ensure this item stays within the UK and ideally returns to Scotland and so we will speak to and encourage any interested Scottish organisation that could support its purchase and future display.”

The two-part seal is said to date from 1322 and is especially unique as most similar pieces were destroyed when they became broken or unusable.

One theory is that cracks on the edges, as a result of the pressure applied when stamping the seals into beeswax, may have caused them to be thrown out or put aside and then simply forgotten about. The stamp is engraved with Saint Margaret, the founding saint of Dunfermline Abbey, and the the royal arms of Scotland.

At one point they were inherited by an Ebenezer Henderson from Dunfermline, a member of the Astronomical and Royal Antiquarian societies.

The Department of Media, Culture and Sport’s reviewing committee on the export of works of art and objects of cultural interest, which advises the government, has said it would extend the current bar if there was a “serious” intention to raise funds.

In The National today, pro-independence, campaigners the Scottish Resistance call on the Scottish Government to be that serious bidder and pay for the seals, or risk losing a “vital part of our heritage” forever.