It emerges that InHouse Communications was appointed on Sunday, after a recommendation from fellow Tory Nick Boles, who recently withdrew from the race to become the Conservative mayoral candidate.
The agency was founded by Ex-Conservative Party media handlers Jo Tanner and Katie Perrior last year.
Perrior said Johnson would be appointing top advisors in key policy areas – transport, housing and planning – and would be positioned as the person ‘bringing that talent together’.
‘Our biggest challenge is to make London aware that Boris is serious,’ Perrior said: ‘The publicity is a double-edged sword and can be difficult to control.’
All Londoners can register to vote to select the Tory candidate by the end of September.
Others putting themselves forward include Tory councillor Victoria Borwick, who has hired Media Intelligence Partners MD Nick Wood.