Are the BNP racists?

Yes, it would seem that they are:

SECTION 2: MEMBERSHIP
1) The British National Party represents the collective National, Environmental, Political, Racial, Folkish, Social, Cultural, Religious and Economic interests of the indigenous Anglo-Saxon, Celtic and Norse folk communities of Britain and those we regard as closely related and ethnically assimilated or assimilable aboriginal members of the European race also resident in Britain. Membership of the BNP is strictly defined within the terms of, and our members also self define themselves within, the
legal ambit of a defined ‘racial group’ this being ‘Indigenous Caucasian’ and defined ‘ethnic groups’ emanating from that Race as specified in law in the House of Lords case of Mandla V Dowell Lee (1983) 1 ALL ER 1062, HL.

2) The indigenous British ethnic groups deriving from the class of ‘Indigenous
Caucasian’ consist of members of: i) The Anglo-Saxon Folk Community; ii) The Celtic
Scottish Folk Community; iii) The Scots-Northern Irish Folk Community; iv) The
Celtic Welsh Folk Community; v) The Celtic Irish Folk Community; vi) The Celtic
Cornish Folk Community; vii) The Anglo-Saxon-Celtic Folk Community; viii) The
Celtic-Norse Folk Community; ix) The Anglo-Saxon-Norse Folk Community; x) The
Anglo-Saxon-Indigenous European Folk Community; xi) Members of these ethnic
groups who reside either within or outside Europe but ethnically derive from them.

3) Membership of the party shall be open only to those who are 16 years of age or over and whose ethnic origin is listed within Sub-section 2

Not really possible to describe that as “not racist” is it?