Higginson will take up the role on 18 May. His role will include corporate and crisis comms, media training, PR strategy, creating a speaker bureau and profile raising.
Among ICG's clients, Higginson will work with Camden Town Unlimited to help secure Camden’s future. ICG also provide comms advice to BluebirdCare and Look Ahead Care & Support.
Higginson joined Westbourne in 2013 as head of communications, where he worked for US car sharing firm Uber during last summer's London taxi strikes and was the communications lead on Hitachi Rail's move from Tokyo to London.
At the end of 2014 Higginson set up Justice Delayed Justice Denied, funded by the Telegraph and Guardian Media Groups, to cap police bail at 28 days following the treatment of his wife, The Sun's Whitehall Editor Clodagh Hartley.
Prior to Westbourne Higginson spent five years as political editor of the Metro, and worked as a journalist for The Sun, The People, Daily and Sunday Mirror, The Independent and the Evening Standard.
ICG managing director John Lehal said: "John’s deep and wide media knowledge and proven track record will prove invaluable to our clients. His strategic thinking, creativity and calm under pressure align perfectly with the work we’re known for and where we are going."
Higginson added: "ICG has a trusted reputation for creativity, delivery and careful stewardship of some of the world’s most successful brands. Its back catalogue of awards, client retention and wins through referrals speaks volumes for the quality of its output. I look forward to working with the hugely talented ICG team to help clients respond to the changing media landscape."