The UK Statistics Authority told the Labour frontbenchers they needed to send their aides so they could explain where they were getting their statistics they were using while addressing the public.
The Authority’s chairman Sir David Norgrove said he was concerned about Labour’s “lack of published information” whenever the party made large, sweeping claims about Government policy.
The chairman only gets involved in addressing misleading statistics when uses politically, especially by elected officials.
Labour has already been written to three times this year by the watchdog to warn the party over misuse of data.
The organisation polices any public use of statistics in order to prevent the continued use of false or misleading claims by politicians or anyone else.
When Labour claimed earlier this year Universal Credit would force millions into poverty, Mr Norgrove attacked the party for not providing any type of statistic to back up their claim.
He also wrote to Mr Corbyn in August to tell him it was “unclear” why Labour was telling young people Labour would help to save them £1,000 a year with free bus travel.
Mr Norgrove said: “I am sure you would wish the Labour party to apply the appropriate standards in its use of data and analysis.”
In the most recent letter, he attacked the party for claiming their policy of giving company shares to workers would allow for 11million people “a greater stake in the rewards of their labour”.
The stats chief said: “The Authority has written to the Labour party previously about a lack of published information on sources, assumptions and methods to support statements.
“I would welcome a meeting between your team and the Office of Statistics Regulation to discuss how the Labour party might apply the principles of the Code of Practice for Statistics in its communication of data.”
A Labour spokesman said: “We received a letter this week which did not challenge any of our figures, but was requesting a meeting between officials on how those figures are presented.
“We always strive to be as transparent as possible with our policies, as evidenced by costing our manifesto in 2017 unlike the Conservatives, and always welcome advice on how to do even better.”
In addition to repeatedly sending letters to Labour, Mr Norgrove has also continually told Tory ministers to not make misleading statistical claims.
No dates have been issued yet for when Mr Corbyn and Mr McDonnell’s aides will meet with the Authority.