there were similar pro-austerity arguments after WW2 - great resistance to founding te NHS, nationalising industry etc the Attlee govt prioritised the welfare of the general population over those preaching the vital importance of 'living within our means' - usually popular with those with substantial means the British remembered the 30's as an example of austerity in practice post-war public borrowing and spending were followed by the 'never had it so good' 50's
Nationalising industry was the cheapest course in 1945, and was done on the never never. To take the example of the railways and transport industries, although the share swap is now argued to have been over-generous, it cost essentially nothing at the time. Shares in the Big Four, already hugely depressed in value by the need for post war reconstruction, were swapped for (effectively) government bonds: nationalisation was done by forcing owners of shares to swap those shares for interest bearing government paper. We've been paying for it since. The nationalisation included complete basketcase industries, like the canals, which had been in terminal decline since the 19th century. Buying those was a really smart move. Not.
The same applied, mutatis mutandis, to steel, energy and telecoms: the choice was allowing them to go bust (with hideous consequences given the UK had to export to survive), lending them money under something like the Loans Guarantee Act of the 1930s which would cost cash right now or issuing government debt (dressed up as bonds) to pay for them later.
I'm not sure where you get the idea of 1930s "austerity" from either: the Loans Guarantee Acts pumped huge amounts of money into railways, canals, shipbuilding, particularly the underground in pure Keynesian mode, and then from 1935 the huge increase in defence spending had a similar effect.
What are you claiming was cut in the 1930s? It was an interventionist government that borrowed heavily, came off the gold standard (in 1931) to devalue sterling to improve the economy, formed a national government for most of the period to avoid political infighting, threw vast amounts of cash at industry (not all of it wisely) and generally did everything it could to keep Britain out of the global depression. It didn't entirely succeed: what more would you have had it do? What policy would, say, Syrzia implement that the National Government wouldn't? The Holidays With Pay Act? Raising the School Leaving Age? Slum Clearance? Devaluation? All National Government policies.
The opposition to the NHS was nothing to do with "austerity" either. The BMA and other objected to government involvement in health care which it variously saw as Stalinism or National Socialism. As Beveridge said, he shut the consultants up by stuffing their mouths with gold.