Hartlepool is a seat that has gone Labour in every election since 1945 (known as 'The Hartlepools' prior to 1974) except in 1959, but this somewhat betrays the fact that there have been a few recent elections that were close. The closest was in the 2004 by-election, where a large swing to the Liberal Democrats cut Labour's majority to just 6.5%. A strong result from UKIP in 2015 also had them just 7.5% behind Labour (this election was also Labour's lowest share of the vote since 1931). Most recently, the 2019 Election saw Labour drop 14.8%, ending up just 8.8% ahead of the Conservatives. However, the Conservative vote also dropped by 5.3%, with the Brexit Party taking votes from both parties as well 2017 UKIP voters and getting 25.8%, their 3rd best result in the country and their best in the North East. It's arguable then that this seat might've been a Conservative gain had the Brexit Party not stood, though it's difficult to validate that assertion.

This seat is seen as something of a crucial election (alongside the election for the Mayor of Tees Valley, of which Hartlepool is a constituent borough) for Labour under Keir Starmer as, despite them not losing the seat in 2019, Hartlepool is in the North East where Labour experienced some of their biggest drops in the last election (the Labour vote dropped by more than 10% in 22 out of the 29 seats). With the Reform (formerly Brexit Party) vote expected to collapse, Labour need to not only show that they can win over those voters in order to hold these kind of seats, but that they are at least somewhat improving on their 2019 margin.

Constituency polling should be taken with some caution, they were notoriously inaccurate when used widespreadly in the 2015 General Election. That being said we have two polls using two differnet methodologies showing rather different results. In March, Focaldata produced a MRP projection in the seat had Labour only up 1% but with the Tories up 7%, cutting Labour's majority to just 3%. It also had Reform down 17%, the Lib Dems down 1%, and the Greens, who didn't run in 2019, on 7%.

Survation has done more conventional polling here, though their latest had a rather small sample size of 301, which had the Tories 13 points ahead of Labour, with Labour on 33% and the Tories on 50%. Compared with 2019, this would see Labour 5% down and lower than their previous worst result on these boundaries, when they got 35.6 in 2015, and the Tories 21% up (a swing of 13% from Labour to the Conservatives). It also had Reform all the way on just 1% (down 25%), with the Lib Dems and Greens also on 1%. It also had the newly formed Northern Independence Party on 6% (though their candidate, a former Labour MP) is on the ballot as an independent due to the party not registering in time.

As mentioned before, while these polls do have some merit, things can change a lot in a month (though so far Labour's national polling average has been falling since this poll) and Labour winning is certainly still within the margin of error. Even so, Labour only barely holding this seat would certainly do nothing to ease concerns around the current direction of the Labour Party.