Certainly. The UK routinely and repeatedly jails people for protected speech, including speech protected by international standards. [1] [2] [3]

[1] https://freedomhouse.org/country/united-kingdom/freedom-net/...

[2] "Internet freedom declined in the United Kingdom during the coverage period due to a reported increase in criminal charges for online speech"

[3] "A separate report from The Telegraph found that 292 people had been charged for spreading false information and “threatening communications” under the Online Safety Act between when it came into effect in 2023 and February 2025. Some civil liberties groups expressed concern that the laws were being applied broadly and in some cases punished speech protected by international human rights standards (C3)."

Inciting racial hatred etc is not protected speech in the UK