Voting fraud in Northern Ireland has been widespread and systemic since the foundation of the state, the largest ever study of the subject has found.
Everyone from the UUP, Sinn Fein, the UVF and the IRA has been involved in mass voter impersonation, Professor Stuart Wilks-Heeg of Liverpool University suggests in his study, which was released in advance to the Belfast Telegraph.
He said that Sinn Fein learned from this technique and appeared to engage in widespread voter fraud in the 1980s.
He quotes Brendan Hughes, the former IRA Belfast commander, as saying he had a fleet of taxis at his disposal for voter fraud.
He also said that the UUP used caravans and safe houses where it dressed up volunteers with wigs, clothes and glasses, and said this practice continued for decades.
Using records from courts, the House of Commons, Stormont, the Electoral Office and the media, his report found widespread voter impersonation throughout the history of Northern Ireland and said it was typically used to win seats from other parties on the same side of the sectarian divide.
This week the SDLP in Foyle made an official complaint to the Election Office about the Westminster election, in which the number of proxy votes in the constituency shot up to more than 1,200 from 300 used in the 2015 election.
Sinn Fein won the seat for the first time, and has rejected the SDLP's claims that it was involved in proxy votes fraud.
And the party yesterday rejected historic and present allegations.
Professor Wilks-Heeg cites examples in which unionist parties engaged in nefarious voting practices.
"Young women and teenage girls were more likely to be used for voter impersonation because they were more likely to be let off if there was any doubt," Professor Wilks-Heeg said.
The academic also found that Sinn Fein started to adopt unionist fraud methods in the 1980s and 1990s and used them to its advantage, especially in West Belfast.
He suggests that Sinn Fein manipulated the vote in the 1982 Northern Ireland election so that Martin McGuinness would win a seat.
He cites a Sinn Fein informer who said that it would deliberately start fights or riots to shut down some polling stations early, and was also involved in voter impersonation.
His research examines the widespread abuse of postal voting, finding that the percentage of postal votes in Fermanagh and South Tyrone reached 14.4% in 1974, dropping to just 4.4% in 2010, as electoral reforms took effect.