ONE The only electors whose views matter are the 30-40% of Londoners that bother to vote at local elections – a high level of name recognition could matter a lot.

TWO The inherent element in the UK electoral system that skews General Elections in favour of Labour works in precisely the opposite way in the London Mayoral Election where it’s aggregate votes across the capital that count not seats.

THREE There are substantially higher turn-out rates in outer Tory and Lib Dem areas than Labour’s strongholds giving them a disproportionate affect on the outcome.

FOUR In the last four all London elections for the capital’s boroughs and the London Authority the Tories have had margins in terms of aggregate votes. This was the case even in the very bad years for the party of 2000 and 2002.

FIVE Ken Livingstone succeeded in 2000 and 2004 because a large number of Tory and Lib Dem supporters in the London Authority elections gave him their first choice for the mayoralty. Last time this was about one in six Tories and one in four Lib Dems. Will that seepage happen on the same scale with Boris? Probably not.

SIX As the YouGov BrandIndex surveys repeatedly showed Boris Johnson is one of the best known and most liked politician in the UK. This could make a big difference in second preferences which are likely to play a big part in determining the final outcome.

SEVEN Boris Johnson is not on the board of Jarvis plc.

Having said that Ken is an extraordinary and formidable politician who is going to be very hard to beat. He has made the “Mayor of London” into a well known brand that appears on millions of Oyster cards and official documentation that people carry with them. The incumbency effect will be very powerful. Ken is seen as someone who can get things done.

But to keep his job Ken has once again to convince a large proportion of Tory and LD voters to switch to him in the Mayoral election. That might be tougher against Boris than Steve Norris.

For those who get pleasure watching political contests this “clash of titans” is going to be great to observe, to bet on and to predict.

Mike Smithson