Vanguard have 4 LSE listed Factor ETFs (Liquidity, Minimum Volatility, Momentum, Value), that they describe as being actively managed, but the approach sounds fairly mechanistic. For example, the Value ETF:
The Investment Manager’s quantitative model implements a rules-based active approach that aims to assess the factor exposures of securities, favouring equity securities which, when compared to other securities in the investment universe, have lower prices relative to their fundamental measures of value (which measures may include price-to-book or price-to-earnings ratio, estimated future earnings and operating cash flow).
I am about to buy the Value ETF in my daughters' Lifetime ISAs. For actively (sort of) managed global funds the charges are quite reasonable at 0.22%.
There are a number of "RAFI" (Research Affiliates) and other Factor/Smart Beta ETFs available, which although described as passive, are really rules based along the lines of the Vanguard active ETFs.