Alan Johnson is the latest cabinet member to advocate an emphasis on "core British values" to improve social solidarity. Anticipating today's publication of Sir Keith Ajegbo's review of citizenship classes, he said at the weekend that schools should do more to foster "community cohesion".

Going with the flow of the Big Brother furore he added that, "We want the world to be talking about the respect and understanding we give all cultures not the ignorance and bigotry shown on our TV screens." He continued: "Schools should be a force for good in tackling racism by creating understanding and debating what it means to be British." Along with confirming the good news that the government won't give the Catholic church an about-opt over the sexual orientation regulations, he formally endorsed the Ajegbo report on the Today programme this morning.

Without wishing to fall below the standard for good manners Honest Al has claimed for himself - "I'm a working class boy, I was brought up polite" - I'd guess he's grateful for his turn at leading the government's Great Britishness parade, what with being a contender to be Labour's deputy leader and by extension deputy prime minister. Over recent months the "Britishness" drum has been beaten with gusto by Tony Blair and the suddenly not quite so "tough" Doc Red Top. But even their fervent tattooing has been eclipsed by that of premier-designate Gordon Brown. Knows what side his bread is buttered on, does Al.

So what's this "Britishness" business about? At first sight the enterprise may seem appealing, and Johnson has expressed it in its most attractive form so far. Equating a bedrock national identity with the inquiring acceptance of cultural diversity and historical change has obvious attractions, a rebranding given substance by drawing on more generous strands of Britain's post-war history. It seems to formally extend the embrace of inclusion to those who've previously found the dominant symbols and personifications of Britishness disagreeable if not downright hostile. This may seem to make electoral sense too. Not only does make a friendly offer to those who feel they don't belong in the Britishness fold, it simultaneously invokes the idea of patriotism as an indivisible virtue. It's a dependable way to do good ballot box business even if the product has been modified.

To me, though, all this reasoning looks flawed. For a start "New" Labour's "New Britishness" pitch is essentially disingenuous. Though garlanded with talk of tolerance and membership for all for all, regardless of faith or race, the government's message has mostly been discriminatory. Conceived in a climate of growing anxiety about Islamist subversion and immigrant inflow, it's underlying aim is to soothe some sections of British society by pointing a finger sneakily at others, sometimes even as it claims to be speaking to the latter personally.

Variations on this ploy have been delivered now for months: by Blair and others in their brainless pronouncements about the veil; by Brown in his bullish insistence on incomers learning English; by Ruth Kelly in her speech marking the launch of her unpromising Commission on Integration and Cohesion. The most hideous example was John Reid's dropping in on Muslims in Leyton last Sepember when his patronising lecture about how you can be Muslim and British as well was ambushed by a gobby fundamentalist. And serve the Doctor right. His words weren't really intended to engage Muslims at all but to "reassure" nervy middle England switchers and at the same time to persuade back into the fold those "traditional" Labour voters long taken for granted, who've lately shown by their defections to the British National party that they do, in fact, have somewhere else to go.

Such has been the main thrust of "New" Labour's response to mischievous newspaper conflation of public fears about terrorists within and supposed loss of national identity: a dog whistled promise to make those immigrants behave and those Muslims be British properly, disguised by a thin mood music of fair play. Is anyone buying this sophistry? Perhaps Labour wobblers in Scotland will be wooed back from the SNP, but there the "Britishness" offensive addresses the consequences of nationalist secession, and that is a very different theme. Meanwhile, the serious danger is that this slippery populism will compound the problems it purports to address.

This applies both socially and electorally. The shabbiest aspect of the integration debate has been the implied accusation that minorities alone are responsible for ethnic and religious tensions. The government, the Tories and most of the media have been complicit in this failure to recognise that fear and prejudice among those who see themselves as the authentic British contribute to mistrust and division too. Why should people rush to sign up to something called "Britishness" when its champions are singling them out for blame? As for the tactical notion that this implied intention to bring outsiders into line will stem a leakage of support from Labour to the BNP, word from the ground is at best ambiguous. Some say that Labour's nationalist tack has put more wind into the fascist party's sails. Like Howard Keele in Oklahoma, Nick Griffin's boys think everything's going their way.

None of this is to argue against a debate about how we define core values and how respect for these is squared with the freedom to adhere to various cultural traditions wherever they are rooted and subscribe to diverse beliefs, religious or otherwise. Such conversations should animate any vigorous democracy and all those living in it should feel equally entitled to take part. Moreover, Alan Johnson hit the right note where the incendiary topics of race and faith are concerned. Children benefit greatly from discussing these themes, and such benefits should be fully extended to those for whom the urban polyglot is heard as a distant, alien cacophony. In fact, I'd like to see him go a great deal further, extending the fullest possible concept of citizenship so that it permeates the whole of the curriculum rather than limiting it to the failed timetable gesture imposed by his predecessor Northern Tebbit.

But for this and any broader citizenship project to succeed, a separation must made between the nurturing of basic values in Britain and any demand to sign up to "Britishness" - between, perhaps, a collective moral philosophy and subservience to a national identity. It may be sad that the Union Jack turns off some of the very people it's most important to assist in feeling they belong in Britain, but such is the flag's recent legacy - one that for others gives it its sole, barren meaning. It's vital, too, to recognise that Britain contains millions of people of every colour, of every faith and none, who despite being born here, living all their lives here, maybe even holding a British passport too, have never thought of themselves as British, yet are exemplary members of British society. The same cannot be said of many who boast their "Britishness" most loudly. And, all the while, as the latest British Social Attitudes survey shows, the viability of "Britishness" as a unifying idea is in decline, with less than half the population thinking of themselves more as British than anything else, a fall of 8% since 1996.

So let's talk about core values and let's get down to working out what they should be. But if all in Britain are to share them, let's not smother those values with a flag.

See also
The eccentric art of being British now
Union under threat
Born in Bradford
Britain - what is it?
If it was about the jews