In his economic manifesto, launched today, Boris has promised to set up an independent commission to bring forward proposals on the nature and shape of that new settlement.
That commitment is music to my pro-devolutionist ears.
But I think the case for Londoners retaining a fair share of the taxes they pay is too important to rest on the electoral chances of any single candidate.
So I’m hoping that all other Mayoral contenders will include the same commitment in their manifestos, ensuring that whoever wins has a clear mandate for their negotiations with Ministers.
Too much of this election has been about the taxes Ken and Boris pay. What was initially an amusing sideshow yesterday erupted into a public, profanity laden row which does neither man credit.
What must that have looked like to those cities looking to London as they decide whether to move to the Mayoral system?
With just under a month to go until polling day, there is still time to move the debate onto the more important topic of how much tax Londoners pay to subsidise free prescriptions in other areas of the UK and how much of that tax London should keep in future.