For a £125 budget I'd suggest a new Squier Debut Precision bass.
https://amzn.eu/d/4ADqi4e
From what I've read it's a decent bass for the price. Direct from Amazon and a choice of Sunburst, Black or Red.
If you didn't know, Squier is the budget brand of Fender.
As someone else mentioned, Harley Benton is a great option for a beginner bass, probably better than the Squier and a little cheaper, however I think the relative ease at which you could resell a Squier if playing bass isn't for you, is a big plus.