There are estimated to be ~100k people employed in the JLR supply chain, mainly in the West Midlands with another ~60k jobs directly dependent on supply chain worker spending (source:
https://www.bbc.co.uk/news/articles/cn82edrrknjo). Many of the companies in the supply chain are heavily dependant on their JLR contracts. The UK Govt is looking at various options to ensure the supply chain don't go bankrupt because JLR have suddenly stopped buying. UK Givt is looking at how to support the Tier 1 supply chain, including options such as purchase of JLR parts to keep the factories working, and direct loans to the supply chain to keep their cashflow going.
From a strategic perspective, there is no way that any UK Govt could allow that sort of gutting of its manufacturing capabilities, especially given the current hybrid war with Russia.