Published: 17:16, 12 June 2019
| Updated: 17:16, 12 June 2019
Mr Henderson asked members of his local party to vote for who they would like to see on the final ballot paper next month.
He said they were "overwhelmingly" backing Boris.
Mr Henderson added: "I said I would be honouring the wishes of Conservative party members locally who have overwhelmingly voted for him to be on the final ballot paper.
"I think since it's going to be members of the Conservative party that decide who'll be the party leader from a shortlist of two people, then it's right that they should have a say in the first place.
"My view as a member is we have a lot of very good candidates and my first priority would be to ensure those on the final ballot paper are Brexiteers.
"My preference would be for there to be a man and a woman on the voting paper. We ought to have equality in the final selection."
Mr Henderson has previously accused Mr Johnson of "flogging a dead dinosaur" over his backing of plans for an estuary airport, branded Boris Island.
Tory MPs will vote for their preferred candidate to be PM tomorrow (Thursday).