Boris Johnson's MP brother was one of the surprise supporters at the ex-London mayor's Tory leadership launch.
Orpington MP Jo Johnson, who backed Remain, arrived at the campaign kick-off with father Stanley.
They were joined by former City Hall aides James Cleverly MP, Kit Malthouse MP, Munira Mirza and Daniel Moylan.
The Uxbridge & South Ruislip MP was also backed by several front and back bend colleagues from London and the Home Counties.
They included Theresa Villiers MP (Chipping Barnet), Chris Grayling MP (Epsom and Ewell), James Brokenshire MP (Old Bexley and Sidcup), Adam Holloway MP (Gravesham), Mark Francois MP (Rayleigh and Wickford), Grant Shapps MP (Welwyn Hatfield) and Iain Duncan Smith MP Chingford and Woodford Green).