This week I had a Ukip moment. On a new estate in north London, I found my poor little Polo trapped in a parking bay by a giant BMW which was double-parked.

A woman in a hijab emerged from a flat to berate me for parking illegally. “This is for social housing,” she said. She then got into her BMW. I almost turned into Nigel Farage and ranted at the woman.

I had paid £3.50 to park. You get the picture: law-abiding citizen who pays his taxes for things like... social housing. I bit my lip, thankfully. It turned out the Muslim woman was right and I should have parked up the road.

The incident made me think that maybe there is a tiny bit of racism in all of us – or at least most of us. I have seen it in my own family.

My paternal grandfather liked Enoch Powell and the National Front. My father was not like that but I know that, if he had still been alive, he would have been alarmed at the 2012 headlines revealing that white Britons were now in a minority in London.

I was relaxed about it. Nor, unlike Mr Farage, am I bothered when I don’t hear an English voice on the train. I’m delighted my son has not inherited the ounce of racism left in my bones, which rose fleetingly to the skin this week. It dies out down the generations.

Yet this welcome trend may be about to stall. This week the British Social Attitudes survey reported a hardening of views, warning that Ukip’s rise has been partly fuelled by the “disconnect” between a liberal political elite which accepts immigration and many voters who find it “intensely threatening”.

Mr Farage is right to assert that it is not racist to talk about immigration. Nor is it wise for politicians in other parties to accuse Ukip of racism, because the party echoes people’s real fears.

Politicians rarely make the positive case for immigration or talk about the figures showing that migrants put more into the economy by paying their taxes than they take out by claiming benefits and using public services.

Nick Clegg bravely made the case in his first Euro election debate with the Ukip leader. It didn’t do him much good and – surprise, surprise – David Cameron and Ed Miliband didn’t follow.

There was an election coming, after all. But there always is. So the Tories and Labour often try to outbid each other, promising another crackdown on “benefit tourism” which makes the public think the problem is much bigger than it is. They raise hopes that cannot be fulfilled, unwittingly damaging politics in the process. Rather than reducing Ukip’s appeal, they make many voters hungry for more.

The Tories portray Labour as “soft”. Labour argues that it is tougher on the main issue of public concern – cheap migrant workers taking British jobs.

Yet there is more common ground on immigration than their rhetoric suggests. If you locked Mr Cameron, Mr Miliband and Mr Clegg in a room, they could probably agree a joint statement on the issue: good for the economy but must be firmly controlled; tough action on illegal entry and employers using migrant workers to undercut British ones; taking students out of the immigration figures and not setting unenforceable targets that undermine the case for EU membership (which is also good for the economy).

I have long believed a cross-party approach is the only way to ensure a grown-up debate on immigration. Some senior Labour figures are now pushing the idea. In a timely new book on big issues politicians cannot crack, The Too Difficult Box, Charles Clarke, the former Home Secretary, argues: “It needs creativity and energy but I think that it is the only way in which we can eliminate the poisons which have surrounded our national discussions around immigration for so long.”

David Blunkett, another former Labour Home Secretary, told the Commons this month: “We’ve got to try in our own way across all three major political parties to provide some answers that are credible, because nobody can underestimate the bewilderment and no one should belittle the cry for help from our constituents.” The Commons committee chairmen Keith Vaz and Margaret Hodge, who saw off the BNP threat in her Barking constituency, also recognise the value of a cross-party approach.

Mr Clegg is up for it and would have the most to gain. But, sadly, it is not going to happen soon. While Ukip’s Euro election victory makes a cross-party initiative more urgent, it also makes it less likely – at least before next year’s general election. Mr Miliband believes he has real differences with the Tories and their fixation with caps and targets. Crucially, he is worried that a consensus among the three mainstream parties would only fuel Ukip’s insurgency, allowing Mr Farage to dismiss the move as another stitch-up by the cosy Westminster club.

Cameron the moderniser of 2005 might have co-operated with other parties on immigration. But the Tories’ election script, written by the Australian strategist Lynton Crosby, says they must stick to four issues on which they are strong – the economy, welfare, Europe and … immigration.

I hope that one day, all three parties will see the merits of a common approach to immigration. But I wouldn’t bet on it.

Turning an ill-defined Ed into a man of substance

“What do we do about Ed?” Labour can no longer avoid the question. The party’s MPs are increasingly worried about Ed Miliband’s poor personal ratings and that voters do not see him as a prime minister-in-waiting.

Miliband advisers are frustrated. This week’s important policy messages were in danger of being drowned out by the personal stuff. Tory-supporting newspapers write nasty stories suggesting Ed is not up to the job. Then other papers write stories asking: is Ed up to the job? Then the broadcasters join the feeding frenzy.

True, it’s all self-fulfilling. But it’s also true that there is a problem.

Here’s how Labour plans to tackle it. It will tell voters that if they want a stylish but identikit prime minister who stands for nothing and is the creation of his spin doctors, they should vote for David Cameron.

If they want a PM who is a spin doctor’s nightmare because he can’t eat a bacon sandwich, but a man of substance and principle who wants big change for the benefit of the vast majority, they should vote for Mr Miliband.

So there you have it. Another election dividing line: style versus substance.