Boris Johnson is certainly having a 'good Olympics'. The newspapers are full of summer stories about his potential threat to Cameron's leadership.

I'm not convinced that Mayor Johnson will become Tory leader or prime minister. First, as Steve Richards pointed out in a good Independent piece this week, there are major barriers to him even being in a position to compete. Would he remain so popular if he dumped his London role in order to get back into parliament, for example?

Second, while he is undoubtedly popular in London, I wonder how his style would translate to the rest of the country. Let's not forget that David Cameron encouraged other cities to vote for an elected mayor on the grounds that "every city needs a Boris". The result was hardly a resounding vote of confidence in the politician who personifies the role of elected mayor.

Third, while mayor of London is an important job it is arguably not as tough and nowhere near as serious as being even a cabinet minister let alone PM. Johnson remains untested through the grind of ministerial life and as a shadow minister he proved not only gaffe prone, but also not particularly interesting or innovative.

Finally, I hope the Tory party and the British people will see through his facade. My challenge to Johnson is: why do you put on an affable, unworldly, untidy persona when that is so obviously not who you really are.

I worked with Johnson while I was home secretary. He proved utterly ruthless in cutting off Met Commissioner Ian Blair at the knees immediately after his election. I don't believe people should make their way in politics by trashing other people, but that was his clear aim in getting rid of a commissioner who had led the Met during a time of falling crime and reform. Others have commented on Johnson's lack of team spirit - I can remember him turning up so late for a COBRA meeting on Olympic security that the meeting was ending as he burst into the room.

I know people are disenchanted with 'traditional' politics, but it is wrong to respond to this by suggesting that elected politics is something you can fit in between writing your lucrative newspaper column and appearing on television gameshows. To become a senior politician, you will have put other parts of your life like your career and family on the back-burner in order to even get to a position where you can face the electorate.

Fighting and winning an election involves an immense amount of energy, stamina and quick-thinking as you meet and talk to hundreds of people each day. You need to have thought through your position on a whole range of issues or you will soon be caught out. And quite rightly. Being an elected politician is an immense honour and a great responsibility. You are a voice for those you represent; you embody the mandate granted in our democratic system. This isn't something that you should suggest can be achieved lightly.

Acting as if you woke up in City Hall one morning and are now engaged on Boris' Big Adventure; artfully ruffling your hair to suggest that you're not really bothered about your appearance; turning up late to important meetings so that other important people have to wait for you are designed to make you stand out from the political crowd. They are a tactic as clever as any other political tactic and people should not be taken in by them.

This post originally appeared on Progress Online.

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