This is not an academic essay but just my own observations. The old fashioned, working class Labour movement were just that. The employees, many uneducated academically but many vocationally, who fought for their rights till eventually through the trade union movement, inspired by Marxist theory, but I don't think the majority of the white working classes in Britain when the party first won an election would be that keen on mass immigration or gay marriage.
Wind forward to the 2000s, possibly the 1970s onwards, and we have what can only be called the champagne socialists. The middle class super-rich academics living in North London who not just believed somehow they should take money away from people exactly like themselves, but bring about a social revolution, not based on economic equality, which is a utopian fallacy which goes against a free society, but social equality where everyone is treated the same. Logical as far as it goes, why should women be paid less or black people banned from renting houses? These laws went through around the 70s, and despite women still earning less and older people being rejected for work (how did that happen exactly), evening out the playing field as much as physically possible, plus some swinging too far by positive discrimination, where some ethnic minorities gain more protection than everyone else, which is just a glitch in the system, the middle class left have not stopped, but now want complete social engineering.
Now to me, looking at the reasons for and reactions from the Labour movement after the industrial revolution, giving equal rights should be part of all civilised societies, but this does not include open borders, allowing protection for immigrants who attempt destroy our values and society, redefining marriage, and worst of all repressing free speech by claiming some topics are not up for discussion, eg EU membership, whether global warming is a threat, whether gay marriage is real marriage and restricting immigration, even when the same arguments are by older immigrants. This is crossing the line from socialism which is essentially an economic movement to allow equal power for the majority, the workers, with social equality on top so no minority or other group was treated badly.
I would suggest following Britain's Labour movement and subsequent laws, this mission was completed, and any further efforts besides some fine tuning are fighting for more power than is required for its own sake. The modern intellectual 'metropolitan liberalism' movement espoused by wealthy academics, the ultra-bourgoisie detested by Marx (despite being a fairly good representative of it himself), with little or no similarity to the early working class movement led by indigenous poorly educated and paid white men. I say men specifically, as despite personal economic hardships, the wider economy meant once in a steady job the majority of married couples were able to buy and run a house on one income, so the woman, again, had a socially separate role and most until the 60s were quite content to do so, taking jobs as and when they chose, until forced to work more and more since as house prices took off from 3-4 times income to over 10. I expect many women (and men) today would prefer to choose which partner worked, as well as the children who rarely spend any time with their working parents compared to when one was usually at home when they were. And ask the average coal miner their opinion on the environment? Do you really think the white working class, who formed the vast majority of the workforce in the 50s, what they felt about their impact on the environment and they'd probably have tarred and feathered you. The working class were not and are not environmentalists, without generalising too far most are not particularly concerned with rain forests, global warming, and wouldn't be likely to know or care where the rain forests are besides Hampstead Heath.
So, as stated somewhere yesterday, the working class Labour core voters now are so far away from where their party has gone, some who bought their council houses or did well under Thatcher in the trades have turned, while the others solely on ideology rather than what would be best for them feel obliged to vote Labour. But besides already having what they needed in the way of worker's rights, there is absolutely no historic record of the 'liberal' social attitudes of the modern age. Spinning off from righting social and economic disadvantages to try and engineer society to reflect your own personal ideology is not left wing but pure totalitarian madness. Imagine Bevan, Rowntree, Elizabeth Fry and the entire Quaker movement, and the founding fathers of the union movement giving half a damn about whether the form for housing benefit was in Hausa or Aramaic, or whether the BBC had enough black people in a Question Time audience? As far as they were concerned if everyone, equally, had a roof over their head, food in their bellies and decent working conditions the rest was up to them, as long as they didn't want too much more as the state would simply remove it in taxes.
So my suggestion is there is nothing left wing or socialist about today's liberal movement to engineer society the way they don't just want it to be, but like tyrants before them, exactly how it must be. Yes, if you have ten shops in a row one must be owned by an Ethiopian if that is the local population division. You must have people with one leg in the workplace and will remove the other one if they disagree with gay marriage. Homophobia will become a capital offence. Marriage can include as many consenting adults as they wish, as otherwise you would be discriminating against alternative sexuality (that's coming, trust me), and the latest abomination under god, nature or society depending on your beliefs, being able to replace your birth certificate if you disagree with the sex you were born as. We have sunk to a level of decadence now below Sodom and Gomorrah, they were just the blueprint and I think this latest travesty has finally surpassed anything they were capable of imagining. Just do a DNA test and count the X and Y chromosomes if you disagree with me. None of this is economic or pro-working class or poor, it is a hideous destruction of every part of a civilised society brick by brick, and now by entire walls. Soon there will be nothing left of it at all.