I first spoke to Douglas Carswell about the possibility of his joining Ukip more than 18 months ago. Around that time there was considerable publicity about the number of MPs that our Treasurer Stuart Wheeler was having lunch with – the figure of nine was mentioned.

Mr Cameron’s January 2013 pledge for a referendum on the EU succeeded in stopping defections from happening. The Prime Minister did just enough to keep his people onside. But then I started speaking seriously to Douglas a few months ago. He was now looking at Ukip as being the only realistic option for bringing genuine change to this country. Yes of course we both agree that the majority of our laws should not be made in Brussels. And that uncontrolled and now rapidly increasing net migration into Britain was the current major issue.

But our political agreement ran far deeper than that. Both Douglas and Ukip agree that the current front benches are run by careerists with virtually no experience of the real world at all. They are in it for themselves and the country and the wellbeing of our people comes as a much lesser priority.

It was quite a victory for Douglas that the coalition agreement included a promise to bring recall – the means by which we can sack MPs – into law, since he had led the campaign on this issue for some time. Yet nothing has happened. The reality is that our current political class have no intention of making the radical change that the British people now want.

So the decision was made; Douglas would join Ukip. And I was absolutely thrilled and delighted. but his announcement to me that as a matter of principle he would resign his seat and force a by-election is, I think, the most honourable and decent thing that I have seen in my political lifetime.

In the wake of the European elections in May this year the entire commentariat said that Ukip would not win a single seat in the General Election of 2015. Well, that view has been changed over the course of the summer in which opinion polling has shown that Ukip is now in the lead in some constituencies. Indeed, I have made my own decision – as reported here first – and have now been selected to fight the seat of South Thanet in which my team and I have a very good chance.

The answer to the question of how many others might defect – which is the classic media response – will be answered by the by-election. There are an increasing number of Conservative and Labour back benchers who not only support Ukip fully in what they are trying to achieve but view the impact of open-door immigration and its effects on the lives of ordinary people with increasing urgency.

Ukip’s rising stars Show all 7 1 /7 Ukip’s rising stars Ukip’s rising stars Suzanne Evans A Tory defector who has only been in the party for a year. She was rapidly appointed national communities spokesman. A former BBC reporter who now runs a PR agency, she has won plaudits within the party for her confidence in front of the camera. Ukip’s rising stars Steven Woolfe A barrister from Manchester whose father was mixed-race and mother was white. He was invited to become financial services spokesman before he had even joined Ukip. Now an MEP, his ethnicity and northern upbringing are in strong contrast to the Ukip stereotype. Ukip’s rising stars Margot Parker A local businesswoman who impressed Ukip’s hierarchy with her spirited campaign in the Corby and East Northants by-election 18 months ago. She was elected as an MEP for the East Midlands last week. She has a no-nonsense style which party chiefs believe will be persuasive on the national stage. Ukip’s rising stars Patrick O’Flynn A former Daily Express journalist who became Ukip’s director of communications and was a strategist behind the Euro-elections campaign. An experienced performer on television who is close to Mr Farage. With his media background he could become a culture spokesman. Rex Ukip’s rising stars Amjid Bashir A restaurateur of Pakistani lineage who is one three Ukip MEPs representing Yorkshire and the Humber and currently speaks for the party on small business. After his election he said: “Here I am... of Asian birth, of Asian parentage, Muslim, and I have been selected by this so-called racist party. It disproves that completely.” Rex Ukip’s rising stars Louise Bours Until her combative appearance alongside Piers Morgan and Joey Barton on Question Time last Thursday, she was one of Ukip’s lesser-known faces. The new MEP for the north-west is a former actress whose full name is Louise van de Bours. Her northern credentials could come in handy in wooing Labour-leaning voters. Ukip’s rising stars Paul Nuttall Long serving activist from Merseyside who became Ukip’s chairman in 2008 and deputy leader two years later. He is a key weapon in the party’s attempts to broaden its appeal to working-class voters in the North of England. PA

Indeed this week’s immigration figures and the ever deeper troubles of the eurozone clearly illustrate the point. So if Douglas Carswell wins this by-election and those backbench MPs with a favourable view of Ukip believe they are more likely to win their seats as Ukip than as Tory or Labour then more will follow.

The Clacton by-election is of huge significance not just to the future of Ukip but to the whole of British politics. It will indeed be our high noon. And this great news comes on the day that a report into the elitism in Britain has been published. With three of the highest posts in this country being held by men who went to Oxbridge it is yet another example of how the aspirational workers in this country are being let down.

The River Thames, the source of our trading wealth throughout history, is now a glistening waterway diving a large purple chunk of the country. It’s in this part of the country – Essex up along the coast, and the South and Eastern parts of Kent – that the workers who get up earliest in the morning and get home latest at night have seen that the future lies with Ukip.

You can see it in the polling for the General Election constituencies, with Tim Aker MEP, who was selected as our candidate for the Thurrock seat last Autumn, on course to take a historic victory in that seat, down the river from Clacton.

Purple Van Man is increasingly seen as the choice for the aspirational workers of this country – who believe in fairness and hard work, who have suffered at the hands of regulation and uncontrolled immigration, and who over the past few years have put their money where their mouth is and voted Ukip not just in European Elections – we came top in the Eastern Region and the South East – but in local and county elections too.