Rory Stewart is Minister of State at the Department for International Development, and is MP for Penrith and The Border.

Copeland? It had been a Labour seat almost continually since 1910. The last Conservative MP was born in 1879. And the last time there was a by-election in Cumbria against a sitting Conservative government, 1983, the Tory support collapsed by 11,000 votes. So how on earth did we win – delivering, according to John Curtice “the best by-election performance by a governing party in terms of the increase in its share of the vote since January 1966”?

The 20 days I spent campaigning – in ex-mining villages, such as Moresby or Cleator, in estates around Whitehaven, in Lake District villages, and repeatedly in Keswick – haven’t left me with any simple answers. In fact, I was often confused. One man told me that he couldn’t decide between voting Green or voting Conservative; another was torn between UKIP and the Liberal Democrats. Some wanted to discuss peddlars – others were interested in Fair Trade for banana farmers in the Leeward Islands. The £500,000 with views of Bassenthwaite seemed often to be voting Lib Dem, while a 1930s council estate at the bottom of the hill turned up Tories.

So what were the common themes? Election professionals felt that that the by-election was going to be won on the nuclear industry (the largest local employer), and on Brexit – and those issues dominated our election literature. But few mentioned these issues on the door-steps, and some that did were anti-nuclear Remainers. Instead, in my experience, people voted for us because Theresa May was our leader, and Trudy Harrison our local candidate.

I must have met a hundred people who said that they didn’t like the Tories, but liked the Prime Minister. They volunteered that she “had a very difficult job”, that they “wouldn’t like to be in her place”, that she was “working very hard”, and “doing well” (even if they added a Cumbrian “so far”). Increasingly, if I was stuck for something to say I just raised Theresa May. Somehow the Brexit vote, and her approach to it had struck a chord: people were prepared to empathise instead of criticise, and believed in her seriousness.

Then there was Trudy. By the end of the campaign, I did not meet anyone who didn’t know that she was the local candidate, who had been born in the local hospital, and had a husband welding in the nuclear plant. They felt she was a “fighter”. And she was amazing on the doorsteps – seven days a week, 14 hours a day: funny, attentive, and engaging.

But despite all Trudy’s best efforts, she could not physically meet every voter. Which is where the campaign structure mattered. The party, which combined local field campaigner and press officers with teams from London, managed to get all the leaflets, posters, canvass sheets and pledge cards distributed across one of the largest constituencies in England. Three MPs were assigned to play different parts in coordinating the campaign, and were up most of the time (Andrew Stephenson, John Stevenson, and, in a lesser supporting role, myself).

Neighbouring associations were assigned zones (my own under the tireless Laura Kay, for example, took responsibility for Keswick and the east). There was a fantastic turn-out from prospective parliamentary candidates (some of whom – like Tom Lowther or Louis Mosley for example – came again and again). And – perhaps because they were not forced to visit – over a hundred MPs came and worked more enthusiastically, and stayed longer than I have seen in any previous election. All of this – reinforced by tens of thousands of phone calls made by 750 volunteers – was vital in making sure people knew who Trudy was.

The dominant policy issue seemed to be West Cumberland hospital. The local newspapers ran front pages suggesting that the “Tories” were planning to savage it. UKIP produced a “Save the NHS” poster, the Lib Dems ran hospital polls, and Labour delivered hospital petitions at the door of Number 10, implied that voting Conservative was a vote for killing babies, and ran a candidate who was a local doctor and ambulance driver. And yet this did not ultimately effect Trudy’s support. Instead, people acknowledged that she cared about the hospital – not least because she and all her four daughters had been born there. A Labour member told me he was voting for Trudy because there is a Conservative government, and she is the only hope Copeland has of getting Westminster to focus on the hospital.

And that, of course, was the common background. The long years of Labour rule in Copeland and Whitehaven did not deliver. When the first Labour MP was elected in the constituency in 1910, it was the west coast of Cumbria that was the prosperous part of the county – and many families from my constituency in the rural east, moved there for work. Growth and productivity was supposed to come from the giant industries of the west. So when the mines closed, a succession of Labour MPs and council leaders between 1936 and 2010 spent millions to attract new factories, often from overseas.

But in each successive decade, the grants dried up, the factories closed, machinery was sold off, and new grants were put in place to start the process again. After 75 years of this strategy, most people in Copeland faced a choice of either working for the nuclear industry or being without a job. Meanwhile, the conservative rural east of Cumbria, which had not received these industrial grants, continued to be dominated by small businesses (92 per cent of people work for businesses employing less than ten, and 27 per cent of my constituents are self-employed) and had one of lowest unemployment rates in the country.

No-one – however, left-wing their politics might have been – believed in Jeremy Corbyn’s ability to turn this situation around. And the majority of people concluded that after almost a century of Labour rule, it was time for Trudy and Theresa May. Our task now is to give Trudy the policies and the support, and demonstrate what a Conservative government can do for the people of Copeland.