I WAS on a train south of London recently when a man in the next seat started talking loudly and somewhat drunkenly into his phone. 

He was evidently a GP talking to his receptionist. After some talk about a prescription for Mrs X and a named little boy, he said: “If I had my way we would turn away all these foreigners” and “the unemployed,” he added for good measure. 

When he finished the call, I asked him to keep his racism to himself. 

He accused me of being “one of those Labour types” (guilty as charged) and then said he was Ukip — “Britain for the British — we’re full up.” 

He explained that these immigrants bring their children to the surgery “when they just have a cold, it’s disgusting.” 

I was shocked — such public expression of racist views has been unusual in recent years. 

But the advance of Ukip has permitted such people to be openly racist. So we ignore Ukip at our peril. Ukip is a xenophobic, populist party, and the evidence is now sufficient from the myriad individual statements to their core anti-migrant rhetoric, to say that they are a racist party. 

While evaluation of the scale of the threat and the debate about how to combat them will be considerable, tackling racism and telling the truth about migration must be central. 

The truth which unites right and left in Labour — migration is good for our economy, good for our society, and good for our communities. 

Rather than shuffling nervously when Romania is mentioned, we should remind all and sundry that 2,151 NHS doctors qualified in Romania, and emphasise how our NHS and the care of our parents and children is reliant on migrants. 

When jobs are mentioned, we should remind people that in 2008, after the big EU migration, vacancies in Britain reached record levels — because migration boosts the economy. 

While proper regulation of the labour market, including higher and better enforced minimum wage legislation, controls on agency recruitment practices and much better training would be very welcome and long overdue, it is because all workers need that protection. 

We should not concede that migrants have caused widespread reduction in wages. We should note that reductions in wages have been caused primarily by austerity and this wouldn’t have happened with the limited regulation now proposed. 

The pernicious idea, too often peddled, that communities are fractured by migration should be rejected. Those who know most about it and live in the most multi-racial areas, Britain's vibrant cities, decisively rejected Ukip. 

Indeed, in the aftermath of the Olympics, with the national recognition of Britain’s multicultural success, opinion poll ratings of racism shifted radically downwards. 

We need to speak out and speak up confidently for Danny Boyle’s Britain — rejecting the backwards apocalyptic darkness of Ukip’s “vision.” 

The casual Islamophobia, so evident in the current debate about Birmingham schools, needs to be rejected too. 

We must indeed stand up to Ukip, racism and fascism and its backward ideas. Determined work to drive them back is essential — but we shouldn’t exaggerate their significance either. 

The long-term trend is away from racism. That Ukip garner 59 per cent of their support from the over-65s (37 per cent in the population) and only 9 per cent from under-34s ( 29 per cent in the population) speaks volumes — they are a voice from the past, with voting memories from the days of Enoch Powell. 

Polling evidence demonstrates that by a large margin, Ukip support comes from former Tory voters, and some non-voters, with only a small minority of Labour voters shifting. Ipsos Mori analysis (aggregate of 2013/14) suggests that 41 per cent of Ukip supporters were 2010 Tory voters, as against 12 per cent from Labour. Some 18 per cent of Ukip were C2DE working class Tories in 2010, as against 9 per cent Labour working class. 

Ukip’s working-class support, to be sure, has grown but in the period since 2010 when Labour’s working-class support has grown faster. The working-class Tory, the Powellite and the Thatcherite blue-collar voter has shifted to Ukip. 

The insecurity and fear of austerity Britain should make them and the worried previous Labour supporters open to clear arguments from the left — but we have failed to connect sufficiently with a clarity of message, so giving space to the populist with the candy-floss arguments, which taste sickly sweet for a moment and then melt away. 

We must get better in expression and policy, become more representative, making it clear and evident whose side we are on so as to win back lost working-class voters. 

But any temptation to give an inch to their arguments must be resisted. That racist doctor on the train must never again feel free to be racist. 

The big majority, including many of Ukip’s recent supporters, can be convinced that Ukip is pernicious and bad for Britain. 

Labour must not shrink from our responsibility to make and win that argument.

The doctor, like many racists, is also stupid. He gave me his name — so a complaint, witnessed by my companion, a newly elected MEP, will be winging its way to the appropriate authorities.

Steve Hart is chair of Unite Against Fascism. This article is adapted from a speech given to the Stand Up to Ukip, Racism and Fascism conference on June 14.