Geordie Finishing School for Girls, BBC Three

If you're reading this review, you'll probably be expecting a sarky analysis. It invites that - wow, posh girls with unpronounceable names have to work in a Newcastle chippy! - but the programme, which sent four Home Counties fillies up North to compare lives with four Newcastle lasses, hit on something so important that we should force MPs to watch it.

Aside from the usual solipsism that all teenage girls have in common - both sides discover that the other has a heart and means well - what GFSG showed is that the divide between the haves and the have-nots in Britain is now so wide that it can only lead to trouble: we have made a wasteland and called it society. The wealthy have grown much wealthier in recent years and, even though levels of absolute poverty have fallen, relative levels have rocketed: the poor are getting richer - but slowly, slowly, while the wealthy race ahead. Books like The Spirit Level make clear the damaging consequences for all of such inequality for physical and mental health, education and obesity, among other factors. It's not the level of poverty, it says, rather the gap between the wealthiest and the poorest.

This may sound like a pointless, perhaps even patronising, harping on about social inequality, but if you fast forward GFSG by a few years, you will see two cultures whose incomprehension of one another has bred the resentment of an underclass and the hostility of an overclass, one intractably dependent on the other, the other oblivious to or resentful of the one. Hell, you see that today; only the relative luxury of the past 20 years has obscured the breach. As times get tougher, the fissures become broader and clearer and the consequences for all of us worse.

These girls cannot help the privilege or poverty they were born into, but what has clearly failed the girls from Newcastle is any sort of mechanism for remedying their situation. (And no, the sympathy of four horsey girls won't do it.) For a plenitude of reasons - from low state educational standards to a monopolising of the professions by the upper-middle classes - the ways of advancement are blocked. Governments have tried the superficial regeneration of Tyneside but the resulting museums and "luxury" flats are as distant from the local girls as the Wallace Collection or the George V. The Newcastle girls work in menial jobs while the southern girls don't work at all, yet the Geordies' jobs don't take them anywhere.

One of the southern girls attends an officer training corps in Wales because she likes the confidence it breeds: where are such structures for the northern girls? Who do they look up to? Tyneside's most famous daughter is the ghastly Cheryl Cole; she offers no hope of intelligence-based success, no example of the tenacity of gradual achievement.

We hear about "rebalancing" our economy away from financial services and towards manufacturing, as if we will suddenly be able to give everyone north of the Watford Gap a job making smocks or superconductors. Get real. The rebalancing we need is between the haves and the have-nots, where we don't give the have-nots handouts but opportunities - or better still, rebalance society to the extent where they can make their own opportunities. If Geordie Finishing School for Girls finishes one thing, it should be the limp myth that we can ignore the inequalities of our "society".

• Watch Geordie Finishing School for Girls on the BBC iPlayer
• Buy The Spirit Level on Amazon