Re: I doubt she'll ever be Home Secretary, but...
Tories are far more profligate with the public finances - https://fullfact.org/economy/labour-and-conservative-records-national-debt/
What happens is the Tories make providing services more expensive by introducing a "market", which has only approved suppliers, so that products and services now are more expensive for the same outcome.
This lets the tories funnel public money to their cronies why claiming record levels of investment in our public services.
As an example of tanking the public finances, and screwing sterling, Brexit should loom large.