The latest 2011 census information includes a table of languages spoken in England and Wales. The information is in Table QS204EW.

This shows that in Cornwall the number of people whose first or preferred language was Cornish totalled 464. Only those aged three and over were counted and the total relevant population in Cornwall was 515 880. The Cornish speakers are 0.09 percent of the relevant population.

In the rest of England there were 90 people who put Cornish as their first or preferred language and 3 in Wales; in some places only one person put Cornish. London as a whole had 31 speakers, the most outside Cornwall.

UPDATE 31 December 2012 The published detailed ethnic data table CT0010EW, with write-in responses, does not list Cornish. In Cornwall 95.8 percent of the people are identified in the undifferentiated group English/Welsh/Scottish/Northern Irish/British.

ORIGINAL POST 11 December 2012
The Office for national statistics (ONS) has published the national identity data from the 2011 census. The figures are in Table KS202EW here.

There are several combinations of national identity of course but the main figures of interest for Cornwall (the unitary authority area) are:

English-only national identity: 59.3 percent of the people of Cornwall, 315 525 people
English and British: 7.0 percent
English and other combinations: 3.2 percent
Total English/English combined: 69.4 percent, 369 581 people

Cornish-only national identity: 9.9 percent, 52 793 people
Cornish and British: 1.0 percent
Cornish and English/Welsh/Scottish/N Irish/British: 2.9 percent
Total Cornish/Cornish combined: 13.8 percent, 73 220 people.
(The second and third Cornish groups are mutually exclusive)

British-only national identity: 15.3 percent, 81 631 people
British and any other combination: 9.2 percent

In numbers the largest census national identities in Cornwall are: English only, British only, English combined, Cornish only, British combined, Cornish combined.
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