We had state aid with Jaguar, Triumph Meriden and British Leyland. It didn't solve the basic problems. We were too inefficient ( too many man hours to produce cars/ motorbikes ) and the cars were unreliable or deliveries of finished cars were often late because of strike action.
Not really my point but... arguably the BL problem was state aid stopped too early. BL were a very similar company to Renault, and the French government ploughed through to see them hit some kind of viability. We, meanwhile, cut the funding just when we had about sorted things out. The major problem then was we had some cars which were reasonable dynamically (Maestro, Montego) but appallingly styled. What they needed above all was a re-skin, and there was no cash for that.
So we sold to British Aerospace with the commitment they didn't sell for a set period... upon which they promptly sold. No investment in the engineering, more a partnership with Honda which was fine when it lasted... but when they sold to BMW instead of Honda (a private company taking, quite rightly, the better financial deal, but not the best deal for the company) it meant they had limited engineering base and had to start from scratch. Cue massive losses while developing some half decent cars and, again, the plug being pulled at just the wrong moment really, when they had their new mid range car all set to go... along with the Mini of course, which BMW kept.
A bit of strength of will, and BL could have been the ones buying shares in Nissan and controlling their destiny.