It was Gordon Brown who brought up the notion of a British national day, telling a Fabian Society conference this year that Remembrance Day was the nearest Britain came to having such an event. Critics suggested the idea was self-glorifying, or something only younger nations would desire.
But the BBC has conducted a poll of more than 5,000 people and found the most popular date for a national day, backed by 27%, was June 15. Next most popular was VE day, then D-day, according to the poll carried out by the BBC History magazine. The chancellor's suggestion of Remembrance Day came fourth.
Historians were bemused at the choice of June 15 because assent to Magna Carta is considered to be an English rather than British event, predating the British union by centuries. Magna Carta was a series of written promises between the king and his subjects that he would govern England according to the customs of feudal law.
A lecturer in history at the University of London, Tristram Hunt, said he was pleasantly surprised by the choice. "To be honest, I think it's exciting that this great constitutional and democratic moment has been chosen. I see it as a foundational moment in British history.
"But really, if they are going to do it, they should have it on Remembrance Day. It is one of the fundamental elements that comes with Britishness."
Dennis Kavanagh, professor of politics at Liverpool University, said: "I am absolutely flabbergasted. Most school kids wouldn't even know what it was all about. Children might learn a bit about it in primary school, but there's very little British history taught now, particularly medieval history."
1 Anniversary of Magna Carta (June 15 1215) 1,334 votes
2 VE day (May 8 1945) 1,039
3 D-day (June 6 1944) 686
4 Remembrance Day (November 11 1918) 568
5 Nelson victorious at Trafalgar (October 21 1805) 524
6 Abolition of slave trade (March 25 1807) 321
7 Napoleon defeated at Waterloo (June 18 1815) 195
8 Birth of Churchill (November 30 1874) 146
9 Cromwellian Commonwealth established (May 19 1649) 95
10 Reform Act passed (June 7 1832) 94
Source: BBC History magazine