We need greater diversity of experience and ideas in parliamentary politics, but the trend seems to be going in the opposite direction.

There's no doubt Maurice Glasman made a fair point when he recently told the Labour Diversity Fund (in a poorly recorded 35 second sound bite dignified by the Guardian as an 'interview') that the experiential base of the Labour leadership is 'too narrow'.

There is of course nothing wrong per se with Ed Miliband, Ed Balls and others following the quintessential insider route to Parliament (PPE at Oxbridge, think-tank, special adviser). And to observe that both Miliband and Balls took the fast track is not to be critical of either man. After all, if you are a youngster with political ambitions and the ability and opportunity to do so, why not take the most direct course? But viewed systemically, the lack of diversity pinpointed by Glasman is problematic.

According to Glasman, Labour is dominated by "Oxbridge graduates, particularly economics graduates, politics graduates, social scientists and lawyers", making it difficult for the party to connect organically with the working class.

Of course the narrowness is both different and worse on the other side of Westminster, where a direct descendent of William IV leads a cabinet of millionaires. But then the Tories have historically never been a party of the majority.

Despite the best efforts of speech writers, spin doctors and image consultants to model aspiring politicians as everymen, life experience does count.

To the disaffected punter on the street who feels that 'all politicians are the same', the similarity of parliamentarians' backgrounds is galling.

The sameness in backgrounds of many within the political classes not only contributes to public disconnect from Westminster, it also narrows the idea base. Good thinking emerges from what people have seen and done, as much as from knowledge or intellect.

Take for example the recent New Labour revival tract The Purple Book. Around three quarters of the self-described 'modernisers' who contributed to the volume were educated at Oxbridge, Harvard or Edinburgh, or had spent time as special advisers: a rather heterogeneous gang to come up with 'progressive policies' to reinvigorate Labour. This may go some way to explaining the quaintly narrow focus of the book.

Aspirants who enter the political bubble early and stay on the inside also learn a certain set of social attitudes and practices. Winning is what counts. The media buzz becomes all-important. The electoral cycle is everything. Information is to be managed and used tactically. The purpose of communication is to win, rather than to actually communicate. Language is deadened. Sound policy and ideological conviction are expendable in the quest for tactical advantage. Appearance is everything. These are the skills, priorities and perceptions that are acquired on the insider-track.

At worst, the insider mentality can metastasize into a shared outlook that is elitist and implicitly anti-democratic: just get those in the know in the room together and let them sort it out.

Ed Miliband's personal commitment to a different kind of politics that is more open and democratic is in ample evidence - why else the painstaking consultation process on Labour's future? - but the broader challenge is to open up the system.

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