Chris Grayling is MP for Epsom and Ewell, and Secretary of State for Transport.

It’s sometimes too easy to underestimate an opponent. We’ve certainly done that in the past few weeks. We can’t and mustn’t make that mistake again.

When I wrote on this website last year that we should not underestimate Jeremy Corbyn, some commentators ridiculed my argument. And it was very easy to do so. His party was in disarray. His leadership was in doubt. We were comfortably ahead in the polls. In parliament today, his party remains chaotic – but, last month, he indeed increased Labour’s share of support

None the less, in that the general election we secured more than 42 per cent of the vote. Whatever the rights and wrongs of the campaign, it’s a level of support that we could only dream of when I was first elected in 2001. It’s the kind of backing that Margaret Thatcher won in her heyday.

But underlying that result is a big challenge for us: one that contributed to the disappointment of the election campaign, and one that remains very firmly in place for the future.

If you are much under the age of 50, you have no real memory as an adult voter of left-wing politics, and  ofthe damage it can do. When Margaret Thatcher fought and won her battle with Arthur Scargill, when Michael Foot was fighting as Labour leader on a platform of unilateral nuclear disarmament, a large part of our electorate was at school – or not even born.

When our major industries were run by civil servants in Whitehall, when you had to order a new telephone from government and there was only one model available which took months to arrive, and when nationalised industries lost money hand over fist, some of those electors were on the swings in the park. To them, the IRA is in the history books. It’s more than 20 years since the first ceasefire, and thankfully the worst of the troubles are a distant memory.

So the battles of the past that we fought and won will have to be fought and won all over again if our country is not to be destroyed by the craziness of a left-wing Labour government in the future.

Time and again during the election campaign, voters were promised something for nothing. You can have more “free” money for public services, more pay, no tuition fees, an unlimited amount to spend on infrastructure…and more and more. And the only people who would pay the bill would be the rich and big companies.

Even were that true, even if the sums added up, we’ve done that before – and it leads to disaster. Jobs and people go elsewhere. There’s a reason why London is the fifth biggest French city, why French politicians rush to London to campaign and why French unemployment is so high. It’s because France’s high taxes on individuals and businesses have driven them out of Paris and elsewhere to come here. It is why Spanish students study, and then face the prospect of 50 per cent youth unemployment or moving abroad (notably to the UK) to get a job.

After seven years of government, with some tough decisions, we’ve seen the opposite. Today, we have the lowest unemployment since the 1970s, and more people are in work than ever before. Going down the French socialist route carries a price, and the French socialists have just paid it at their election. I’d rather not give Jeremy Corbyn the chance to repeat their failed experiment.

So we need to spend the years ahead getting to those voters who were lured by his policies, and show and tell them how damaging those policies would be for this country and our next generation. It’s the historic duty of Conservatives, and we must not shirk from it.
One of the best pieces of political insight I saw during the campaign was a cartoon of Corbyn dancing down the street, throwing money in the direction of a cheering man at the roadside. Except, that the man’s wife was whispering in his ear: “he’s got your wallet”. Corbyn in government would spend spend spend, but the money would be ours – and we would soon find out that neither we nor the country could afford it. That’s a message we will have to get across loud and clear before we all next head to the ballot box.