Mark Reckless
Ukip candidate Mark Reckless is the clear favourite to win the Rochester by-election Getty

"There ain't no black in the Union Jack, so send the buggers back." A disgusting sentiment, but one which sits at the heart of the country's right-wing politics and fuels its most well-known policy proposal: the forced repatriation of immigrants.

Mark Reckless, the Tory-to-Ukip defector set to win the by-election in Rochester and Strood, summoned the dark souls of far-right racism during the election hustings, when he appeared to suggest some European migrants would be made to leave the UK if it quit the EU.

He has faced a fierce backlash. Labour said it was an example of the Ukip mask slipping, while the Conservatives said he was being "very iffy". All political parties have been known to use dog whistle tactics to appeal to voter prejudices. Are Reckless's critics right? Is this just another case?

A furious Reckless later said his views have been misrepresented by his opponents. And Ukip offered a clarification: existing EU migrants would not be forced to leave if it took power.

The robust response of Ukip and Reckless – who turned the tables on the Tories and accused them of being "BNP-lite" for implying in election literature that immigration made people feel unsafe on the streets – suggests there were no sinister intentions behind his comments.

Reckless is not racist. But plenty of potential voters are. Journalists asking the opinion of Rochester locals often report comments like "send them all back" and "immigration must stop".

According to an ICM poll on behalf of the thinktank British Future, 25% of Britons think all immigrants should be repatriated. The notion of immigrant repatriation appeals to more Britons than we might like to admit.

It started when the UK experienced a wave of immigration in the post-WWII years. The then-Labour government invited Commonwealth citizens to help rebuild the country and staff its public services, like the NHS and transport system.

This infuriated nationalists, even more so when the migrants settled and didn't return home. It saw the birth of the modern repatriation movement, later picked up by the fascist National Front and BNP.

Encapsulating the hysteria on the right over the government's immigration policy in the 50s and 60s was the 1964 parliamentary election in Smethwick. The Conservatives used the slogan "If you want a nigger for a neighbour, vote Liberal or Labour". It was less dog whistle, more foghorn. They won the seat.

Enoch Powell
Enoch Powell WikiCommons

In 1968 Tory MP Enoch Powell made his infamous "rivers of blood" speech, in which he prophesied violent social unrest across the UK as a result of mass immigration, which he called "literally mad". He proposed voluntary repatriation.

Groups like the National Front seized on Powell's words and took to the streets in subsequent years, tormenting immigrant and ethnic minority families. There were violent attacks, bricked windows, arson and worse.

For years, the BNP – admirers of Powell's notorious speech – proudly preached a forced repatriation policy. But they dropped it in 2010 in favour of voluntary repatriation, using the carrot of a financial payout for immigrants and their descendants who agree to return to their countries of ethnic origin.

Ukip hasn't done itself any favours. Nigel Farage, the party's leader, has spoken favourably of Powell's 1968 speech. He said he supports the "basic principle". And a book for sale on the Ukip website, written by Sarinder Joshua Duroch and called Enoch, I am a British Indian, says it has found "common ground" with Powell.

Perhaps the angry reaction to Reckless's comments, and the perceived message of repatriation, shows how far we've come from the 1950s.

It should be a warning to those tempted to tap too much into immigration prejudice. A portion of the electorate may agree with you. But the vast majority doesn't.