Conservative unemployment claims questioned
Conservative Party claims unemployment in some areas fell by up to 60% are based on "wrong data", it is claimed.
Benefit claimant counts rather than official unemployment statistics have been used by some Tory candidates.
A research historian said the claims were based on "wrong information" and questioned the legitimacy of their use.
The Tories said data used was the best at a local level, but it is the only one of the main parties to make claims using Jobseekers' Allowance figures.
Both Robert Halfon, in Harlow, and John Baron, standing in Basildon and Billericay, claim unemployment has halved, while Rebecca Harris's literature in her Castle Point campaign claims unemployment has dropped by 60% over the past five years. These figures are based on the fall in the number claiming Job Seekers' Allowance (JSA).
However, the Office of National Statistics (ONS) figures show an unemployment drop of about 20% in those seats.
The ONS says online "the number of unemployed people in the UK is substantially higher than the claimant count".
Jonathan Portes, director of the National Institute of Economic and Social Research, said: "The number of people on job seekers' allowance is not the same as the official definition of unemployment because many people who are unemployed don't claim JSA.
"But, JSA figures at the local level are accurate, but it is not correct to confuse JSA rates and unemployment."
"Ideally, politicians should be clear on the data they use. JSA is meaningful but different from unemployment."
This week, addressing a crowd in Calder Valley, David Cameron referred to a poster saying "unemployment is down 61% here since 2010, that's a record we can be proud of and get out and sell".
The ONS figures show unemployment actually fell 28% between May 2010 - when unemployment was at 3,200 - and December 2014, when it stood at 2,300 in Calder Valley.
'Independent Commons' measure'
Prof Sir Deian Hopkins, a trustee of the Institute of Historical Research Development Trust, said: "The question you want to ask is whether this illegitimate, is this wrong in an election to give people the wrong information?
"Well, of course, this is what [those involved in] elections have always been doing."
While Treasury Minister and Witham MP Priti Patel hasn't used JSA figures, West Suffolk MP and fellow Treasury Minister Matthew Hancock claimed in a press release unemployment had fallen by about 60% in his seat since 2010. The ONS figures suggest unemployment in his constituency has remained flat for the past five years.
In September 2010, 3,500 were unemployed in West Suffolk it was 3,400 in September last year according to the ONS. Mr. Hancock did say he was using JSA figures.
A Conservative spokesman said: "This [questions surrounding the use of JSA figures] is nonsense. This unemployment measure is provided by the independent House of Commons Library - and for constituencies they are the most up to date and most reliable numbers to use.
"They are used by MPs and candidates across the country, regardless of political party."