You can do it, Boris - just wow us with your true grit

I admit the thought that Boris Johnson could seize power in the capital still seems bizarre. But that's because I, and I suspect many others, have got used to assuming that London's Conservatives must always lose.

That unjustly neglected political commentator Bridget Jones explained why when she summed up a mood that gripped cool Londoners for the best part of two decades. Tories like Johnson were nothing more than "braying bossy men having affairs with everyone, shag-shag-shag left, right and centre, and going to the Ritz in Paris, then telling all the presenters off on the Today programme," she told her diary.

And anguished Conservative moderniser Jo Ann Nadler even produced a book, Too Nice to be a Tory, in which she laid into Johnson's "posh twit routine" for reinforcing the impression "that Tories speak a language no one else understands".

Times change and Johnson's supporters maintain that he has metamorphosed from the buffoon who infuriated Ms Nadler into a potential statesman. They wave detailed policy announcements at anyone who doubts he can not only win but also provide serious leadership.

I went through them and found much to admire. But for a man who boasts that he tells it straight, I did detect a slippery habit of sliding for the door whenever tough questions had to be answered.

For instance, Johnson favours zero tolerance policing to attack the yobbishness that blights urban life. A senior officer did a rough calculation for me and reckoned that the Met would need 10,000 more officers to bring New York-style law enforcement here. If that's what Johnson wants, he should say we must pay for extra police with higher taxes. He doesn't, of course, because tax rises will alienate potential supporters.

He also rages against the exorbitant cost of housing, while rejecting the pseudo-solution of the high-rise developments that Ken Livingstone has inflicted on the city's skyline. He wants affordable houses families will want to live in, which is good to hear. Yet he never suggests building new homes on the green belt because that would upset voters in Tory-supporting shire seats, not least in his own constituency of Henley.

There are no painless answers in politics. If Johnson has the strength of character to level with the electorate, he'll prove he's more than just another celeb. If not, his career in public life will remain a posh twit routine.