I have written to the MD of The New Tottenham Singers asking that he (or his Webmaster) remove all references to Tottenham Community Choir and all copied content from his site, also to invite him to reconsider their repertoire so that it no longer contains material that was chosen for, and had previously been performed by, TCC.
I await his response.

(Later addition): it seems that most of the ‘copied’ content, and the defamatory comments, have been removed from the NTS site. I thank them for that.