While last week's Conservative Party conference will be remembered more for Theresa May's cough than any policy announcements, it was striking how the party sought to soften their stance on key issues such as immigration. Yet, what I call the 'mainstreaming' of far right ideas will not be reversed overnight nor any time soon. A mere two weeks ago, Foreign Secretary Boris Johnson attacked young people for having "split allegiances" between Britain and the EU, while Secretary of State for International Trade Liam Fox criticised the media for not obeying the government line on Brexit. We can see it too in Morrissey's return being greeted with cheers in much of the media despite his increasingly dodgy pronouncements on Islam and UKIP. To some these might appear to be relatively benign events, but demonstrate the extent to which British politics has followed a course increasingly favourable to far right ideas.

The vote to leave the European Union in June 2016 was driven by immigration more than any other issue. My book, English Uprising: Brexit & The Mainstreaming Of The Far Right analyses the Brexit vote within the context of Britain's ugly history of anti-immigration politics and the extent to which ideas of the far right have become increasingly normalised in 21st century Britain.

Following the rise of the BNP and then UKIP, mainstream political actors were less and less prepared to confront myths perpetuated about immigration by the radical and extreme right. In many cases they co-opted their rhetoric, egged on by an influential and hysterical right-wing press. An early example of this was Home Secretary David Blunkett's claim that schools were being "swamped" by asylum seekers in 2002. More recent examples include David Cameron's "multiculturalism has failed" speech in 2011 or Theresa May's Orwellian 'Go Home' vans, rolled out in 2013.

One would perhaps expect that after Brexit, this process would slow down as voters angry about immigration had their voices heard. Yet, we can see plenty of evidence for its continuation since Theresa May became Prime Minister after the vote in July 2016. May immediately sought to embark on a hard Brexit – principally designed to curb immigration into the country. At the Conservative Party conference in October, May opted not to bridge the divide between Remain and Leave or attempt to unite the country but embarked on an attack directed against the 'elite' in a manner highly derivative of radical right wing populists across Europe. She promised to:

"put the power of government squarely at the service of ordinary working-class people [. . .] because too often that isn't how it works today. Just listen to the way a lot of politicians and commentators talk about the public. They find your patriotism distasteful, your concerns about immigration parochial, your views about crime illiberal, your attachment to your job security inconvenient. They find the fact that more than seventeen million voters decided to leave the European Union simply bewildering."

May failed to acknowledge that over 48% of the country had voted to Remain and that Brexit reflected a deeply divided country rather than an overwhelming mandate for leaving the European Union. She went on to argue that "too many people in positions of power behave as though they have more in common with international elites than with the people down the road, the people they employ, the people they pass in the street. But if you believe you're a citizen of the world, you're a citizen of nowhere."

May's populist turn was not as new as some commentators believed it to be. May's co-option of rhetoric normally used by the populist radical right was a continuation of the Conservative Party's attempts to do the same prior to Brexit. For example, Immigration Minister James Brokenshire argued in 2014 at a speech to the Demos think-tank: "For too long, the benefits of immigration went to employers who wanted an easy supply of cheap labour; or to the wealthy metropolitan elite who wanted cheap tradesmen and services – but not to the ordinary, hard-working people of this country."

Significantly, May's strategy of winning over UKP voters appears to have worked. In the 2017 snap general election, held in June, UKIP's vote plunged. The party had won the 2014 European Elections and in 2015 won nearly four million votes – by far the biggest victory for a radical right party in British history. UKIP expert, Professor Matthew Goodwin had argued that the Labour Party was faced with an "existential crisis" as a result of UKIP's rise and that the party was 'no flash in the pan'. Yet, in the election, their vote plummeted to around 600,000 – less than two percent of the national vote. The Conservative Party, (who, despite losing their majority, won the most parliamentary seats) by adopting a hard Brexit stance designed to appease those concerned by immigration, had simply stolen any incentive for voting UKIP. Whilst the party may have been decimated, its ideas on immigration and multiculturalism most certainly have not been. When UKIP's one MP – Douglas Carswell – left the party in March, claiming that following Brexit it was "job done" for the party, he was in a sense correct. The Conservative Party has, on issues ranging from grammar schools to immigration, become indistinguishable from the insurgent radical right party.

The rise of the more moderate UKIP destroyed the extremist British National Party after 2010, which is currently a husk of its former self. By making immigration a key issue in its programme, they had stolen a key incentive for voting for the BNP. The Conservative Party has now done the same to UKIP, thereby further normalising anti-immigration politics. This is how 'mainstreaming' functions and it should be a cause of concern for all who wish to uphold liberal, tolerant values.

Dr Paul Stocker's new book English Uprising: Brexit And The Mainstreaming Of The Far-Right is out now - Buy it from Rough Trade here