In the run-up to local government elections in England in May, there are fresh calls for on-demand postal voting to be scrapped.
The government argues that voting by post encourages people to take part in elections, but critics say the system is vulnerable to fraud and is leading to organised ballot rigging that has skewed election results in some towns and cities.
Take the example of Woking in Surrey with its leafy lanes, nice housing, and good commuting for London. Returning Officer Ray Morgan, who oversees elections for the borough, is not a happy man.
It is his job to check that elections in his town are run according to the rules.
But he admits - with remarkable candour - that it hasn't been possible. "Sadly, I don't think any of the elections that I have personally officiated over since 2006 have been totally fair and honest. None of them."
In 2012 Mohammad Ali, a 35-year-old engineer, stood for the Labour Party in Woking but lost by a margin of just 16 votes to the Liberal Democrat candidate Mohammed Bashir.
Mr Ali was suspicious. So he turned detective and set about finding out what had led to such a narrow defeat.
In the two months before the election he says the population of the ward increased by more than 10%. "We started checking them and we found a lot of them were ghosts. We'd knock on the door and ask, 'Do you know Mr So and So?' 'No, I don't'."
He discovered the "ghost" voters had been used to obtain postal ballot papers, which were filled in illegally by activists in favour of his rival.
Mr Ali took his findings to an election court, where the judge in the case, Richard Mawrey QC, ruled there had been fraud and overturned the result, leading to a by-election.
The lawyer who represented Mr Bashir says his client denies any wrongdoing and argues that he shouldn't be held responsible for the corrupt practices of others.
Mr Mawrey says the case is the latest example of how the availability of postal ballots has enabled the manufacturing of votes on an industrial scale.
"Postal voting on demand, however many safeguards you build into it, is wide open to fraud… on a scale that will make election rigging a possibility and indeed in some areas a probability.
"Now I know that there is a very strong political desire to keep the present system. What I'm saying is that if you keep the present system, then however many safeguards you create, fraud and serious fraud is inevitably going to continue because that is built into the system."
The on-demand system allows anyone who is on the electoral register - in England, Scotland, or Wales - to ask for a postal ballot rather than go to the polling station. No reason is required.
The government is introducing tighter controls on enrolling to vote, known as Individual Electoral Registration. People will have their identities matched to other officially held information such as national insurance numbers.
Councils will also be required to check all signatures accompanying postal ballot papers against those on the vote application form. Currently only a sample is checked.
But critics say the changes won't stop campaigners and activists putting direct pressure on people to influence their vote.
In Derby, a smartly turned out man in his 20s - who doesn't want to be identified - has direct experience of how this works.
"Campaigners came to the house and they asked my mum to vote for them... one of the people put the cross in the box for her and said, 'There you go, now you can just sign it and we will take it off you.'"
The man said his mother gave in to stop the activists repeatedly coming to her door, and that she cared more about making them go away in the end than who she voted for.
"That is not voting, is it? If someone is coming and physically putting a cross in a box for you, that is your right snatched away from you, isn't it? It happens to the elderly and the vulnerable mainly, they are the easy targets - those who don't speak much English," he added.
He says this is happening to others in his community year on year, but nobody wants to speak out for fear of being criticised or looked down on - even though it is illegal to fill in someone else's ballot paper.
Earlier this year a report by the Electoral Commission included Woking and Derby in a list of 16 areas at "higher risk" of electoral fraud.
Many of those areas have large South Asian communities but commission chairman Jenny Watson says it's not a problem exclusive to any political or ethnic group.
"The data on prosecutions shows that people from all kinds of communities have been convicted of or have made allegations about electoral fraud, so it isn't an issue that is only about South Asian communities.
"But we heard a number of allegations, often strongly felt and often based on first-hand experience about behaviour in some communities often with close links to Pakistan or Bangladesh, and that did give us cause for concern that there may be some voters in those communities that aren't able to cast their vote in the way they would wish."
Another area on the list is Pendle, in East Lancashire, represented at Westminster by Conservative MP Andrew Stephenson.
He too believes electoral fraud is a problem and thinks the government should end postal voting on demand.
"In different parts of the country, there have been Conservatives, there have been Liberal Democrats, there have been Labour activists arrested and charged over postal vote fraud, so this is not a problem which affects only one political party.
"The government should really look at going back to only allowing postal votes to people who have a genuine need for a postal vote, everybody else should turn up at the polling station like they always used to have to and be able to cast their vote. Everyone should have confidence in a democratic system," Mr Stephenson said.
But Cabinet Office Minister Greg Clark said postal ballots were an important way to ensure that people accessed their right to vote and the number of cases of reported fraud remained low.
"We want to encourage people to vote, but it should be the people entitled to vote and to exercise their vote legally. And what we should be doing is making sure that the procedures are tight enough to capture and then punish very severely those that abuse the system," he said.