If Scotland leaves the Union, will the saltire of St Andrew (the diagonal white cross and blue background) be removed from the Union Jack?
Absolutely not. The Union Jack is not a simplistic statement about the territories that form the United Kingdom—not least because it appears to overlook Wales. Rather it is a complex symbol that describes the history and compromises over centuries of international relations. In 1606, James VI ordered the design of the first “Union Flag” (pedants call it this still, but since the 17th century it has been commonly known as the “Union Jack,” the name endorsed by Parliament).
The Union Jack is already anomalous as the red diagonal cross of St Patrick is in the design. Northern Ireland, though a Union province, is not a separate kingdom and so should not have this separate status on the flag. This is partly because Éire did not adopt the cross of St Patrick as its national flag in 1937, preferring to hoist the tricolour. The Union Jack also appears on dozens of ensigns and specialist flags. At the least this ubiquity will ensure its preservation. Four other countries also fly the Union Jack on their national flags: Australia, New Zealand, Fiji and Tuvalu.
Scottish independence does not entail republicanism. An independent Scotland would remain part of the Commonwealth on the model of Australia or Canada. The current British sovereign would remain monarch, as James IV’s heir. And 400 years-plus of unionism that have forged Britain, would not be wiped out.
The symbol of that union, the Union Jack, will continue to fly over Westminster.