Tracy Brabin visited Switch Mobility in Sherburn-in-Elmet along with Mr Khan to inspect the 30 electric buses being readied for delivery.
The pair, who described each other as “old mates” toured the factory which has already provided 67 electric buses operating in London’s fleet.
And the Labour London mayor, who was re-elected earlier this month after local elections which saw the opposition defeated in the former stronghold of Hartlepool, acknowledged that the manufacturing expertise needed for the buses could not be found in the capital, saying “London can’t succeed without Yorkshire doing well.”
Mr Khan said: “We need these buses in London but we can’t make them. We’ve not got the skilled workforce. If this factory was in America, Canada or Japan, they’d be bragging about it. But it’s in Yorkshire, I’m blown away.
“London can’t succeed without Yorkshire doing well. It’s on me to say thank you. It’s the opposite of trickle-down economics, it’s about being equal partners.
In a piece written for the Yorkshire Post yesterday, Mr Khan said London should be an “an ally rather than an adversary” to the region, and implored on politicians to stop pitting the regions against each other.
But Tracy Brabin, who was elected as the first female metropolitan mayor in the country earlier this month, said that levelling up powers should be handed back to local government.
She said: “It’s important that we make an impassioned plea to the government to say ‘leave levelling up to us.’
“Give us the power and the money and we can help you deliver on your levelling up targets and support our communities - but you can’t do it in Whitehall or Westminster. We have to be able to have the power of our destiny.
“The government has gone a bit cold on devolution, but we are in an opportunity to help government. It’s not just about North and South, it’s about cities and towns.
“It's about having a real commitment to equality, inclusivity, all across the region, so that everybody rises together.”
It came as both mayors paid tribute to Kim Leadbeater, the sister of the murdered MP Jo Cox, who announced last week that she is standing to be Labour’s candidate in Batley and Spen after Tracy Brabin’s mayoral victory sparked a by-election.
Sadiq Khan said: “I was, to be brutally blunt, totally traumatized by Jo’s death. It takes a great person to step into those shoes, and Tracy stepped up.
“I’ve met Kim a number of times, one of the things I feel is that at a time when she was grieving, she took on board what Jo was about in terms of bringing people together. She’s got much more to contribute.
“Kim, Tracy and Jo are all great examples of strong women who lead from the front.”
Tracy Brabin said: “I think she’ll be an exceptional candidate. It’s not for me to say who it should be or shouldn’t be. It was an absolute privilege to be an MP for the town where I grew up.
“Labour offered - and I offered - tangible goals to make life better. And that will happen in Batley and Spen. Whoever is the candidate will focus on deliverable elements and I think we will win Batley and Spen and it will stay Labour.”
Applications are open for the candidacy for the Batley and Spen by-election, with the party's National Executive Committee (NEC) to draw up a shortlist on Saturday and members choosing the final pick on Sunday.