Zac Goldsmith has been chosen as the Conservatives' candidate to run for London mayor in 2016.
The Richmond Park MP was backed by 70% of voters in an online primary to be the Tory to fight for the chance to follow Boris Johnson into City Hall.
Mr Goldsmith said the biggest challenge London faced was housing and promised to fight hard to win the mayoralty.
He said: "I am honoured to have been chosen as the Conservative mayoral candidate and I will work tirelessly to repay that debt.
"I have campaigned hard as an MP, delivering for my constituents and I will fight just as hard to become mayor so we can build on the progress under Boris in making London work for Londoners."
Mr Goldsmith, who inherited a fortune from his industrialist father Sir James, is an outspoken critic of expansion at Heathrow - like Mr Johnson - opposing a third runway at the west London airport.
He has also said he wants to ''mend our politics'', boost high streets, improve transport and provide a healthier environment.
If elected, the environmentalist is expected to step down from the Commons, triggering a by-election.
Mr Goldsmith said: "In the last seven years London has come a long way. Under Boris, London now leads the world in business, tech, media, art and culture - benefiting from unprecedented investment. It is why so many people want to live, work and do business here, and it is also putting increasing pressures on our city.
"We have seen record investment in our transport network, but we will need to continue that investment just to avoid grinding to a halt - while at the same time continuing to bear down on the cost of travel so that it delivers value for money for Londoners.
"Our living environment is facing increasing pressure, and we will need to protect, enhance and improve access to our green spaces, as well as radically improving the quality of the air that we breathe.
"But the biggest challenge of all is the housing crisis. Londoners are being priced out of their city and we will need a step change in the number of homes built, and the manner in which they are built."
Mr Goldsmith will go up against Labour mayoral candidate Sadiq Khan in the vote next year.
Mr Khan said: "I welcome Zac Goldsmith to the mayoral contest and look forward to a positive and friendly debate about the big issues facing Londoners.
"This election is a referendum on London's housing crisis, and I challenge Zac Goldsmith to join me in opposing the Tories' Housing Bill, which will make our city's housing crisis many times worse."
Mr Johnson praised his potential successor, describing him as a fearless fighter who is fizzing with ideas.
"I'm delighted for Zac - he's principled, hard-working, and dedicated, he's fizzing with ideas, and he's passionate about London and its people.
"In May next year this city needs its new mayor to be a fighter, someone who's not afraid to knock some plaster off the political ceiling in pursuit of the best possible deal for London.
"Zac Goldsmith is that fighter. He's fearless. He will make a brilliant mayor.
"I have no doubt he's the best candidate we could possibly have to deliver the vital infrastructure improvements, new housing, jobs and growth London's rapidly growing population will need in the years ahead."