The night of 7 May 2015 was one full of shocks for Labour, and Gower, a constituency in South Wales, was the biggest of all. Party officials gathering at Labour headquarters in London to watch the results had prepared signs with the names of Tory-held seats that the party hoped to win, as well as those they feared they might lose. Even Morley and Outwood, the West Yorkshire seat held by the then shadow chancellor, Ed Balls, had a sign ready.

But not Gower, which Labour had held at every election since the party was created – and which fell to the Conservatives in the early hours. Labour staffers hastily made a paper sign and added it to the board already filled with the names of constituencies they had lost. The winning Conservative candidate, Byron Davies, defeated the Labour’s Liz Evans by 27 votes, making it the most marginal seat in Britain.

Two years on, it could again, in theory, be a close fight between the two parties. But in Gower it doesn’t feel like there’s a contest at all. “About the election? Why have you come here, then?” asked Mabel Hughes, a Gowerton pensioner with a mischievous laugh, when I called at her semi-detached home. These functional, granite-paved houses, which were built in the 1960s as social for mineworkers, are now home to a diverse mix of residents with widely varied occupations, and ought to be right at the heart of the contest.

Yet Hughes has received just two pieces of election literature since the start of the campaign: a letter from Theresa May, delivered by Royal Mail, and a leaflet from the local Labour candidate, Tonia Antoniazzi, a former Welsh women’s rugby player who is now the head of languages at a local school.

When I asked for her age, Hughes laughed and replied: “Ooh, too young for you – 17!” Her voting intention has more in common with her professed age than the average pensioner: she will choose Labour on 8 June.

In Gowerton and the constituency’s eastern towns, however, the usual partisan divide – the young mostly vote Labour and the old for the Conservatives – is turned on its head. Here, it is pensioners like Hughes, whose deceased husband worked in Port Talbot, who retain the old habits of Labour loyalty. Many of the constituency’s younger voters are upwardly mobile, with jobs 11 miles away in Swansea, and have more flexible voting patterns.

But neither group is being strongly targeted, unlike in 2015. Although the Labour hierarchy in London was astonished by that year’s loss, the leaders of the Welsh Conservative and Labour parties knew all along that the contest was close, and so they campaigned feverishly.

This time around the two big parties have decided, rightly or wrongly, that the battleground is elsewhere. The week after Theresa May called the election, a poll by the Wales Governance Centre at Cardiff University and ITV showed the Conservatives opening up a 10-point lead over Labour, putting the party on track to lose an election in Wales for the first time since 1922. The data further suggested that the Tories could win a majority of the constituencies in the capital, Cardiff.

And so Welsh Labour has taken a strategic decision to focus on defending the 25 seats it holds, rather than trying to win back Gower or the Vale of Clywd, or attempting to squeeze out Plaid Cymru. The plan is to fight a campaign based on the personality of First Minister Carwyn Jones, who, according to the polls, is the most popular politician in Wales.

As for the Conservatives, they are campaigning to gain seats, not to defend them. Despite the closeness of the result last time, neither side believes there is a contest to be had in Gower. Both parties expect that Byron Davies, a 64-year-old former policeman, will be returned once more as the constituency’s MP.

But that could be a miscalculation. Even as the rest of the election seemingly passes this area by, one policy has caught voters’ attention: the Conservatives so-called dementia tax. In the Lordship of Gower – the picturesque peninsula for which the constituency is named and where the Conservatives need to perform well to offset the Labour vote from Gowerton and Mumbles – I met Ellen Chambers, 67. She was out for a walk on the beachfront. Chambers voted Conservative in 2015 but intends to sit out the contest on 8 June. Her reason? The social care changes and cuts to the winter fuel payment.

“They’re ripping old people off. Why should I [vote]?” she said.

This is the price of Conservative complacency. Having spoken to Ellen and other natural Tory voters in the constituency who are thinking of abstaining, my sense is that the electorate of Gower may yet cause another surprise on election night.

You can find the rest of our consituency profiles from the 2017 general election here.