The key to Hartlepool - and the next election - is not why support for Labour is low among ‘the working class’ (or more precisely among C2 and DE voters) but why support for the Tories is so high.

Hartlepool has a lot of C2 voters (or what the census calls 'skilled workers') and even more DE voters ('semi-skilled & unskilled workers, pensioners, unemployed'). Traditionally this has been Labour’s core vote.

https://www.ons.gov.uk/file?uri=/peoplepopulationandcommunity/populationandmigration/populationestimates/datasets/2011censusquickstatisticsforenglandandwalesonnationalidentitypassportsheldandcountryofbirth/r24ewrttableqs611ewladv1_tcm77-304378(2).xls

Labour’s support among C2 and DE voters at the 2019 election was low but similar to 1983, 2010 and 2015.

(Source: from the C2DE breaks in each of the IPSOS MORI How Britain Voted series, 1974...2019)

Labour had polled poorly among C2 and DE voters before but in 2017 and then again in 2019, support among C2 and DE voters for the Conservatives broke modern historical records.

(Source: same as before)

2019 is the only time in modern elections that the Tories have led Labour among DE voters. This is not because Labour support was much lower than in 1983, 2010 or 2015 but because Tory support was much higher.

The hidden rule of UK politics is that Labour can only win when it comfortably leads the Tories among C2 voters. In 2019, Labour’s margin of defeat among C2 voters was bigger than it has ever been.

The challenge in Hartlepool is not that Labour’s support among the ‘working class’ is low. These are similar levels to 1983, 2010 or 2015, when Labour held Hartlepool. The change that happened under Corbyn is that working class support for the Tories has never been so high.

After Corbyn, the question which Labour should be asking is not why working class support for Labour fell so low but why working class support for the Tories has risen so high.