The government has delayed the publication of an official immigration study - because it is too positive, according to reports.
The Balance of Competencies review covering freedom of movement across the EU was due to be published on Monday.
But now it is unlikely to emerge until the New Year, the Times said.
The paper said Home Secretary Theresa May was stalling because the report was positive about the current rules allowing people to move freely between EU nations.
The review, which is compiled in different parts by civil servants, was commissioned to support David Cameron's bid to renegotiate powers from Brussels ahead of an in-out referendum on Britain's membership.
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The first part has already angered eurosceptics by concluding that Britain's relationships with Brussels was "broadly appropriate".
The latest instalment, which also covers trade and investment and civil justice, comes as debate rages over EU immigration.
In January, restrictions on visas for Romanian and Bulgarian immigrants are being relaxed, with the likes of Ukip accused of scaremongering over a supposed "influx" of foreign workers.
Lib Dem MP Julian Huppert told The Independent the current rules were good for Britain.
“I hope that the report will confirm that”, he added.