The Tesco war with Unilever is a brave British coup

If you ask me, Tesco has pulled off a coup in its pricing row with Unilever. 
I wrote last year that Tesco would only rebuild its brand through behaviour not advertising. Its stance with Unilever trying to hike prices up a whopping 10% is both brace and big. But if you want to rebuild trust and you want to be believed as a leader this is a great start. 
Bernbach famously coined "a principle isn't a principle until it costs you money." This move will cost Tesco plenty of money but