@Natasha_Jay keep an eye on https://www.gov.uk/government/publications/election-guidance-for-civil-servants something specific should appear soon (depending on how much notice the cabinet office had)
There is guidance from 2019 which will be generally the same I expect.
I'd expect any consultations to be paused or at least the results won't be looked at until after.
PS. It's generally not called purdah anymore, what with the sexist (or at least culturally different) origins of the word.