What penalties are envisioned for offences related to threat driven voter coercion?

Representation ofthe People Act 1983

Art. 60 - 85

http://www.legislation.gov.uk/ukpga/1983/2

 (1) Where a candidate is proved to have beenguilty by himself, or by any person on his behalf, of bribery, treating orundue influence in respect of any person who voted at the election.

(voter coercion both)