Four people have been jailed for electoral fraud after a local by-election in Surrey in 2012.
A fifth person was given a suspended jail term following the Maybury and Sheerwater poll three years ago.
Shaukat Ali, Parveen Akhtar, Shamraiz Ali, Sobia Ali-Akhtar and Abid Hussain, from New Haw, were charged over claims that postal votes were being fraudulently submitted.
They were all convicted of conspiracy to defraud at Reading Crown Court.
Shaukat Ali was jailed for 15 months, Parveen Akhtar and Sobia Ali-Akhtar were both jailed for nine months, and Shamraiz Ali was jailed for six months.
Abid Hussain was given a six-month prison term suspended for 18 months.
When the group were convicted in April, Woking council said the local election had been won by Liberal Democrat candidate Mohammed Bashir by 16 votes, but concerns had been raised with Surrey Police before the election about suspicious activity.
After the election, Labour candidate Mohammad Ali made a challenge which overturned the result.
The Conservatives won a subsequent by-election held in September 2013.
The five people who were charged were all relatives of Mr Bashir and were all from the same family, Woking council said.
Council chief executive Ray Morgan said: "Democracy is one of the key pillars of our society. Yet, as this deplorable case highlights, the pursuit of influence and power can corrupt a small minority."