How badly did Labour lose? It was worse than you think.

To secure a majority of one, Labour now needs a swing of 8.75 per cent across the United Kingdom, analysis of the 2015 results by constituency reveal.

In, Cleethorpes, the seat that on a uniform swing would deliver a Labour majority of one, the party trails by 7,893 votes. In the equivalent seat in 2010, Norwich North, Labour was just 3,901 votes behind, and would have required a mere 4.6 per cent national swing to deliver the seat into the party’s hands. An equivalent swing now would see Labour win just 39 seats.

To be the largest party, Labour would have to take 51 seats directly from the Conservatives, up from 27 in 2010, with a uniform swing of 5.3 percent. Nuneaton, the staging post on this metric, has a Tory majority of 4,882, up from 2,069 in 2010.

Nor does Labour have an easier route back to power in Scotland. The smallest SNP majority that Labour must now overcome is 3,718 votes, in Jim Murphy’s old seat of East Renfrewshire. Just 18 of the SNP’s seats have majorities of under 10,000 votes. A six-point swing from the SNP to Labour – equivalent to the one enjoyed by David Cameron against Gordon Brown – would deliver just two seats, flipping Edinburgh North & Leith as well as East Renfrewshire.

To win a majority in England and Wales alone, which the passage of English votes for English laws may now require, Labour needs a 9.45 per cent swing from the Conservatives to win a majority of one. Harlow, which becomes the winning post under that scenario, has a Conservative majority of 8,350 votes. Labour has not won the seat since 2005, when Tony Blair was elected for a third term.

In Labour’s lowest-hanging targets in 2010, the party now faces an uphill task in 2015. North Warwickshire, the party’s number one target, now has a Conservative majority of 2,973, up from 54. Just one of Labour’s top ten targets, Thurrock, has a Tory majority of under a thousand. But even there, the majority has increased from 92 to 536.

To win a majority of ten, Labour would have to win Harlow, Shipley, Chingford & Woodford Green, Filton & Bradley Stoke, Basingstoke, Bexleyheath & Crayford, Kensington, Rugby, Leicestershire North West, Forest of Dean and Gillingham & Rainham. Of those ten, four – Chingford, Kensington, Filton & Bradley Stoke and Basingstoke – have never been won by Labour at any point in its history. All are Conservative-held.

Nor can Labour hope to win power solely by squeezing the Greens. Just 16 seats would return to Labour if the party were to win all the Green votes in those constituencies and to hold onto all its 2015 voters. In contrast, were Labour to gain the votes of Ukip supporters it would be enough to win almost two thirds of its mooted targets – although the reality is that squeezing the votes of either Ukip or the Greens to a sufficient level is probably a pipe dream.

That’s not to say that Labour’s path to power is impossible – a swing from the Conservatives of the magnitude the party achieved in 1997 would be enough to secure a majority of 71. But it does highlight just how difficult Labour's task is, and that 2015 was not the party's 1992 or even 1983. In terms of the scale of the task it was closer to 1931, when Labour took until 1945 to win an election again.