How serious is Cornish nationalism?

The Office for National Statistics has been publishing interesting insights from the last census – perhaps to counter the bad press that censuses get at this time of year, forcing pregnant Jewish women to travel to municipalities in the West Bank – and its latest release shows that 18.1 per cent of people in Cornwall identify as ‘Cornish’.  Whether as their national identity, ethnic group or, in a tiny fraction of cases, their main language, this is an increase from 13.8 per cent in the last census, in 2011.

All of these were write-in responses – despite a campaign by councillors and local MPs in Cornwall, there was no Cornish tick-box – and I suspect the percentage would be much higher if it was. (The ONS declined to include one on the grounds that demand for it was too localised an issue for a national census; 88 per cent of those identifying as Cornish live west of the Tamar.