The two front-runners triumphed in a secret ballot at Conservative Central Office of the most senior party officials in the capital. Voting figures in the ballot were kept secret.
Andrew Boff, the former leader of Hillingdon LBC, also made it through to the next round of the one-member-one-vote contest. The fourth candidate in the line-up is Bob Blackman, the leader of Brent Conservatives.
The shortlisted candidates now go on to a hustings meeting on 14 September. Invitations have been issued to all 38,000 members of the Conservative Party in London. An audience of 3,000 is expected.