There haven’t been many better bits of telly than the five episodes that make up Boys from the Blackstuff , the seminal series by Alan Bleasdale about a group of tarmac-layers in Liverpool in 1982, each cracking under the pressures of unemployment. It started life as a BBC Play for Today before widening out into a series that was bleak and hard-hitting, but also funny and surreal, slow and lyrical, and absolutely gripping. Forty years later, the thing has happened that happens to all good things, if you wait around long enough: stage adaptation.

At least this one has the good fortune of James Graham , the UK’s political playwright par excellence, handling the precious goods, and when it opened at Liverpool’s Royal Court Theatre last year a load of strong reviews followed in its wake. Now it’s on the Southbank (before a West End run), and perhaps landing more softly than it did on the streets where it’s set. It’s immediately clear exactly which streets we’re talking about: Amy Jane Cook’s industrial set plonks us on the Liverpool docks, all gantries and girders and rusty corrugated iron.

The lads file in to report to the dole office, while the dole “sniffers” remain in a permanent state of suspicion that the lads are doing cash-in-hand jobs. Which they are. This sets off a game of cat-and-mouse that propels the first half of the production.

But Graham’s mashing of the show’s discrete storylines into one play feels lumpy. The first half takes a while to .