Boris Johnson appeared today to abandon his tussle with George Osborne to take control of all property taxes in London.
The proposal to transfer further tax raising powers to City Hall was put forward by the mayor's London Finance Commission in 2013.
But in an interview with ITV News Johnson admitted the Treasury was unlikely to hand over the proceeds of Stamp Duty and business rates.
Instead, the mayor thinks the Chancellor will allow City Hall to levy taxes for special projects like Crossrail 2.
The £25bn high speed commuter line would link Hertfordshire and Surrey through a new tunnel from Tottenham Hale to Wimbledon.