When New Labour won in 1997, an early if second-level, priority was the creation of a new city-wide government for London. This was to address a perceived strategic deficit created by the abolition of the GLC in 1986. London, it was argued, was a "world city": the largest, most populous metropolitan area in the EU, the most important financial centre on the planet, and the engine of the UK economy. It was ridiculous that no single figure or body was in charge of it. The 33 separate local authorities which comprise Greater London could not between them hope to provide the necessary leadership, even if they could agree on how to exercise it. A big, important city needed a big, important leader. A mayor along the lines of New York or Paris seemed just the job.
But Tony Blair was sensitive to claims that he was creating a new "tier" of local government. He was also very keen not to (re)create something which could establish itself as a troublesome, opposing political force, as the GLC, under Ken Livingstone, had done in the early 80s. The Government was also alive to the prospect, even early on, that Livingstone wanted - even expected - to be the Labour leader of any new authority, having been spitefully deprived of his former power-base by the Tories.
The Greater London Authority (GLA) was to be a modern, administratively slimline, US-style setup - a mayor, monitored by a small assembly - both to be separately elected by proportional representation, and housed in a purpose-built, energy-efficient glass bubble near Tower Bridge - way downstream from Westminster. Its focus was to be strategic - in other words, it was to take the big, city-wide view of the world, and leave the day-to-day management of Londoners' lives to the borough councils.
The London Assembly has no real powers of its own. It calls the Mayor to account, and can, if so minded, reject the Mayoral budget. Its members - usually those who are opposed to the Mayor politically - appear from time to time on BBC London TV news (or "Children's Television" as it's known to Londoners) but are generally below the radar.
The Mayor, by contrast, does have a few powers. He or she is in overall charge of the Underground and the buses (although not of most of London's extensive overhead rail network). He has responsibility for co-ordinating land-use planning and can override boroughs' planning decisions; and has partial - but crucially non-operational - responsibility for the Metropolitan Police. He oversees collection of the congestion charge, one of Britain's very few hypothecated taxes (the other most important one is the BBC licence fee), the proceeds of which he has by law to spend on transport. That's about it. He has no responsibility for health, education, housing or social services. He does not empty your bins or clean your street. He can raise or lower tube and bus fares, and invest accordingly. Otherwise, he does - and I sincerely wish it were otherwise - relatively little that you would notice.
The reality is that, outside transport, the Mayor's executive responsibilities are few. That, as envisaged by the Blair government, is the whole point. He is not there as a provider or manager of services; but as a figurehead, a champion, an ambassador. He is to sell London, to plead its cause at home and abroad, to commend it to visitors and investors, to make the voice of the vast, impossibly diverse, organically uncontrollable, rapidly growing*, counter-culturally religious, thrillingly alive entity that is London heard in the world.
This is beyond party politics. More than that, it's actually about personality over policy. It's about which of the candidates most clearly says about London what Londoners want to be said about their city. Archbishop Cranmer told us last year** that the choice for Londoners is whether they want their city's voice to be one that says "piffle" or one that says "shit". I would put it differently - perhaps because I am an ordinary priest and jobbing chaplain who is not allowed to say "piffle". I think it might actually be about which candidate most makes you smile.
* Projected population: 9 million by 2020, 10 million by 2030 (Office for National Statistics)