Brown, patron of domestic violence charity Women's Aid, will highlight the plight of more than half-a-million women who will spend today living in fear of a violent partner.
Women's Aid launched the campaign today because abusive relationships often begin as a flattering display of romantic love.
But along with the chocolates and flowers can come the first dangers of unreasonable jealously and possessiveness, which can soon turn into violent and controlling behaviour.
Brown launched the campaign by posing in front of print and outdoor ads showing Valentine themes with a shocking twist, created by advertising agency Grey London.
One shows a single red rose with a message reading: "Suzy, I told you to shut up you stupid cow. It's your fault I hurt you. Pete."
Another says: "Joanna, I love picking you up in my arms then smashing you against the wall. Dave."
Print ads will appear in national newspapers, while radio ads will appear on Virgin Radio, as well as being podcast on the Daily Telegraph website.
In the first burst of radio ads, a male voiceover describes a sinister message he will be sending to his loved one.
All the ads urge women to end domestic violence by logging on to the Women's Aid website.
Brown said: "Domestic violence remains a taboo issue for many and through this campaign we hope to get everyone, not just those who are in violent relationships, to think and talk about the everyday reality of domestic violence for hundreds and thousands of women every year."
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