The London Cenotaph The Glasgow Cenotaph
The London Whitehall Cenotaph, designed 1919, does not have a cross on it because of the diversity of religion and non-religion among the fallen of World War 1 (Sikhs, Muslims, Buddhists, atheists, Jews etc as well as Christians).
The Glasgow Cenotaph constructed in 1927 does have a cross on it and press accounts of the time suggest no controversy over this.
On the history of the London Cenotaph visit
http://www.secularism.org.uk/uploads/cenotaph-a-consensual-and-contested-monument-of-remembrance.pdf
On the history of the Glasgow Cenotaph visit
http://www.heraldscotland.com/comment/columnists/agenda.24352008