Iain Duncan Smith is Secretary of State for Work and Pensions and MP for Chingford and Woodford Green.

Seven months to go before the next general election and UKIP has an MP sitting in the House of Commons. Not of course some unknown activist from the bowels of the UKIP machine, or a local who had been working to unseat the sitting Conservative (remember UKIP junked their original candidate without a local vote). No, the ‘new’ UKIP MP is the same person who has represented the seat of Clacton for the past nine years. The public watching this must wonder at this theatre of the absurd. Yet even with Labour just holding on in Heywood and Middleton, despite UKIP’s boasts, it remains clear that a UKIP vote at the general election adds up to a Labour government.

So if that is the case why did Conservative voters in Clacton, still opt for UKIP at the by-election?

Well, I spent some time in Clacton campaigning and was again struck by how clear-sighted the voters were. What they made clear to me was their frustration, as many had been badly hit by Labour’s great recession, struggling with lower salaried jobs and often falling behind with their mortgages. Although they could see the economy was improving and their prospects were better, they still felt that lack of security for them and their families. They were also frustrated about what they perceived as an influx of immigrants, mostly from Europe, they were adamant that they wanted this controlled in or out of the EU and they wanted to have their say on whether we left the EU. They were also disenchanted with what they perceive as Westminster insincerity.

Gone are the days of tribal loyalty to one’s party regardless of events, instead many were clear that they understood that the by-election was an opportunity to send a signal to the government. Yet, despite all this they couldn’t have been clearer that they were also ready to be persuaded to vote Conservative at the General Election, that they understood the difference in the two votes. They wanted to be sure that what we offered were not just promises but real commitments.

They are clearly tired of the Westminster games played out, the perception that in Westminster politicians make deals to help themselves and not the public. That’s why I don’t believe making an electoral pact with UKIP – as some in my party have called for – is right. Such a process would only convince the electorate that they were right about us and we would deserve to be punished at the polls. Another Westminster stitch up is not the answer to an electorate that wants to make a choice.

They said they were worried about their security and their family’s prospects. This is why with a track record in government of welfare reform, improving education standards and getting people back to work, we now need to show that the only hope for what they crave is to continue delivering the long term economic plan. Our successful delivery of that plan, with our commitment to lower taxes for some of the most marginal and hardworking families, means people’s future security relies on that clear choice at the next election.

But we also have to show them that we have listened and that their concerns about immigration and the EU are central to our plan. That is why our commitment to renegotiation, to deliver much greater control over our own borders and welfare is underscored by our commitment to give the British people their referendum. I was struck by the fact that many still don’t realise that they will decide Britain’s future only if the Conservatives are in power after the next election – that it is only David Cameron who is committed to deliver that referendum they want.

That’s the point. At the next election the public knows it is about who governs the country, it’s not a protest. The real choice is who governs, Labour or Conservative, Miliband or Cameron. UKIP, for all their talk will not govern but they could end up deciding who governs; for as these two by-elections show, a vote for Farage will only help Miliband into Downing Street.

Think of that, Miliband and the most left wing agenda since Michael Foot – higher taxes, more public spending, another recession and no referendum on Europe. The choice gets clearer as we get to the election only if we make the positive case for the Conservative party’ one you can believe in, compassionate and credible. If you want economic security, border control and a referendum on Europe you need a Conservative government.

Actually, Douglas Carswell, the ‘new’ UKIP MP for Clacton was right when he tweeted on 12th March 2014 about voting for the Prime Minister:

For us Conservatives the challenge is to persuade the British people that you have to vote for that by delivering a Conservative government.