By Brian Wheeler
BBC News political reporter
With Channel 4's Big Brother starting its sixth series this weekend, it is time once again to dust off one of the great political clichés of the age.
Millions voted for Big Brother 5 winner Nadia
Almost before the first desperate hopeful is evicted from the TV house, somebody somewhere - probably a politician or a journalist - will claim that more young people vote in reality television contests than take part in general elections.
But is there actually any truth in this claim?
According to programme-makers Endemol, there were 6,363,325 votes cast during the 2004 live final of Big Brother 5.
The total number of votes cast in the most recent series of the BBC's Fame Academy was 8,250,000.
There were 27,128,130 votes cast in total the 2005 general election.
No contest there, then. The House of Commons beats the Big Brother house.
But what about 18 to 34-year olds - the target audience for reality television and the group most often portrayed as being disaffected with politics?
The good news for the politicians is that the expected collapse in the vote among this age group at the 2005 general election appears not to have happened.
According to research by MORI, 21% of people who said they were "absolutely certain to vote" in the 2005 election were aged between 18 and 34, an increase of about 1% on 2001. The percentage of 25 to 34-year-olds who said they planned to vote went up by 3%.
Overall, that translates into 5,696,907 votes cast by 18 to 34-year-olds on 5 May.
If one assumes all the viewers of the Big Brother final are aged 18-34, the programme was, on the face of it, slightly more popular than the general election among young voters.
But these figures do not take into account multiple voting.
Unlike in a general election, there is no bar to the number of votes viewers can cast in reality TV contests and programme makers try every trick in the book to keep the votes - and the cash - rolling in.
Figures on how many times people vote to keep their favourites in the house are hard to come by. The programme makers and Channel 4 say they do not compile such information.
But research by Janet Jones, a lecturer at Aberystwyth University, suggests 54% of viewers will vote once a week during a nine week run.
Ms Jones also found 10.5% of Big Brother viewers voted between two and five times a week and 3% said they voted more than five times a week.
She told BBC News: "This means that over the course of the run, most respondents voted approximately ten times.
"A significant number voted up to 50 times and a minority voted from 50 to 100 times.
"And a few sorry individuals probably fuelled their addiction by voting well over 100 times."
Her research was based on 12,339 responses to a questionnaire on the Big Brother web site.
Although it is far from conclusive, this research suggests the popularity of voting for Big Brother and other reality TV shows may be routinely overstated.
But this has not stopped the government and politicians in general from looking with envy at the mountain of votes piling up for Big Brother, I'm a Celebrity..., Fame Academy and their like - and attempting to learn lessons from it.
One policy document on the Office of the Deputy Prime Minister's website says: "A host of television and radio programmes such as ITV1's Pop Idol and Channel 4's Big Brother encourage viewer polls using telephone voting, SMS (Short Message Service) text messaging or internet voting.
"With such a proliferation of the method, it is difficult not to conclude that there is popular support for e-voting, among a significant proportion of citizens".
Labour's election manifesto promised further measures to boost voter participation.
It is of course, possible to prove almost anything with careful manipulation of statistics.
But next time a politician appears on television claiming Big Brother is more popular than the general election among young voters, it is worth bearing in mind that they are almost certainly wrong.