We citizens of this extraordinary and amazing city will be going to the polls on 1 May to elect ourselves a new Mayor. The polls of the last few weeks have seemed to indicate that this year Londoners really have finally had enough of Ken Livingstone. Personally I still find that difficult to believe: the man who is so far the only person to have held this post is one of politics’ great survivors – and more importantly the issues that have made the headlines about him so far – City Hall intrigues about how a couple of tiny organisations were funded, and how many children he has – seem to me like the sorts of issues which get journalists and political opponents excited, but have no real impact on the lives, and therefore the voting intentions, of normal voters.

It’s no surprise that I will be voting for Brian Paddick – he has a track record of innovative leadership on the London-wide stage, and perhaps more importantly, of doing so in a way which is popular with the local community. He would make a good Mayor. And he comes without Ken’s voluminous political baggage – encompassing everything from campaigning from low transport fares in the 80s to introducing record high ones in the 21st century, from doing odd deals with revolutionary leftwing South American presidents to being one of the biggest fans of City plutocrats.

But then of course there is the second preference choice to be made. And here I stumble across a dilemma which I actually think now faces (even if we haven’t realised it yet!) all Londoners who don’t want to see a Conservative government after the next General Election – which is most of us.

To be clear to start with: I think Boris Johnson would be a complete disaster as Mayor. His various performances over the last few months have entirely satisfied me that underneath the external appearance of a clowning buffoon, there lies in fact….a clowning buffoon. I don’t think he’s really interested in being Mayor of London, and when he did have to make a decision on something, I don’t doubt for a moment that he would do it based on what he thinks would be the interests of him and his friends rather than the interests of London as a whole. He is a true Conservative and I don’t think he should be entrusted with government.

I’m confident that within a few short months it would be clear what a disaster his mayoralty would be – and indeed a taste of what a Cameron Conservative government would be like.

And this is where it becomes a dilemma.

For by being a fumbling, ignorant clown, who when he did anything as Mayor would do so on the basis of unreconstructed Conservative ways, Boris Johnson has it in his power to do more than anyone else could, to deter people from voting Conservative at the next General Election.

Do you think that after a couple of years of Boris Johnson gaffes as Mayor of London, people will be more likely to vote for a new, fresh, Cameron Conservative government?

And indeed if you were David Cameron, seeking to give to the public a taster of what your new, reformed and modernised Conservative party would be like if it were elected into government, would you choose Boris Johnson to be that entrée?

What this means is that those of us who do indeed think that a Cameron Conservative government would be a profoundly bad thing for this country, have a dilemma. Should we pinch our noses and vote for the least worst option for London of the two as second choice in Ken Livingstone (as Peter David has very articulately and persuasively set out on Lib Dem Voice)?

Or should we keep our eyes fixed on the further but bigger horizon of who forms the government of the country, and be prepared to accept Boris Johnson as Mayor of London, as a kind of vaccination helping us to prevent a future Conservative government?

It’s an interesting choice - and one that could well have quite an impact on the future of who win the nation’s government after the next General Election. What do you think?