Since the Budget, the Conservatives have suffered from a few bad headlines and a drop in the polls. Ukip have enjoyed a sudden surge in support. The disgruntled – who have loathed David Cameron’s centrism for years – have pounced: this proves, apparently, that the modernisation project has failed. Time to bin it.

Fortunately, as Oliver Letwin has said, senior ministers don’t believe in running government like a magazine. They “believe in running government like a government". Ignore occasional blips and unpopular patches, overall the Conservative modernisation project is in actual fact very successful, both politically and in regards to policy.

Cameron couldn’t even win a majority in 2010, they howl. Well, the party did gain more seats than at any election since 1931, and did receive a record swing of 5.1 per cent from Labour. Compare that to Thatcher in 1979, who received a swing from Labour of 5.3 per cent. The Conservatives must have been doing something right.

Even now, during a time of severe cuts to public spending, the Conservatives enjoy a relatively high poll rating. Cameron is popular and his party is more trusted than Labour on the economy.

As Professor Tim Bale shows, in a first-past-the-post system, the winning party is the one that hoovers up the most floater voters who sit in the middle of the political spectrum. Quite simply, the Conservative Party – as polling by Lord Ashcroft reveals – didn’t do enough – and still doesn’t do enough - to convince these centre-ground voters to secure a parliamentary majority. That’s the problem.

Still, there are complaints that Cameron is conceding too much ground to the Liberal Democrats and abandoning true Tory values by focusing on gay and green issues. But these are just part of a broad package, and are not incompatible with Tory sentiments on freedom and stewardship. Actually, the coalition government has a whole array of reforms that ought to be very pleasing to Tory activists: a reduction in public expenditure, the use of a veto in EU negotiations, welfare reform, the lowering of income and corporation tax, the dismantling of state control in education, greater control to front-line professionals in the NHS. The list goes on.

But still there is discontent, and threats of resignations to Ukip. And so it becomes clear what is at the heart of all this ill-feeling: doctrinaire libertarianism. Ukip is a party of libertarian purists – those who believe the state or multinational governments should basically have no role in telling institutions or individuals what to do.

Such pure libertarianism has some merits, but two key flaws. The first, and the most major, is that it refuses to acknowledge how culture and poverty in a system of entirely voluntary exchange restricts individual choice, and that the state can play a positive role in rectifying this to expand freedoms.

The second, and most relevant, is that it is rigid, ideological and extreme. These libertarians do not see society as an ecosystem of different – often conflicting - interests with the role of Government being to carefully balance them to achieve the optimum equilibrium between equity and efficiency. Rather, they believe everyone has their own interest which should they be able to pursue regardless of the externalities, except if it is criminal, and government should just get out of the way to allow them to do it.

The result then is that purist libertarians are never satisfied.  Never content until the UK pulls out of the EU altogether. Never happy until public services are entirely independent of state rules and control full stop. Never pleased until the government and the EU stops issuing directives that regulates individual behaviour, such as the smoking ban. No wonder they are perpetually dissatisfied with the Prime Minister.

Such a mind-set applies to their approach to politics, as with many other ideologues. They are not satisfied until conservatism – and their particular form of conservatism – triumphs in every decision and policy of government. Coalition, then, is abhorrent. Such tribalism, disappointingly, misses the fact that, as moral psychologist Jonathan Haidt says, “each team is composed of good people who have something important to say”.

Ironically, if they join Ukip, their only way of gaining real influence in government would be through a coalition. Better, surely to stay inside the party – a coalition in itself – to have real, long-lasting effect. Indeed, as a Conservative who values different perspectives around a table, I’d like those libertarians to stay.

Ryan Shorthouse is the Director of Bright Blue.