Just in case this becomes a case of "Eagleland Osmosis", where things outside the US are assumed to work the same as in the US.
A special case of Reality Is Unrealistic, Eagleland Osmosis occurs when people outside the United States consume American pop culture and start to believe that aspects of their own society work like they do in these imported films and television …
tvtropes.org
Total funding of all pollitical parties in the UK came to less than $50 million in 2022. That wouldn't win a single contested senate seat in the US. Funding for the US 2020 election came to $14 billion.
The relationship between funding of politics and favours/lobbying in the UK is a lot less clear cut than it is in the US. Not least because in the US Congress directly writes the budget whereas the executive writes it in the UK.