Michael Ellis, Minister for Arts, Heritage and Tourism, has placed a temporary export bar on the page.
He said it was “right” to preserve the pages for the nation, adding: “These handwritten and personally signed pieces create an incredibly powerful impression that simply could not be achieved from looking at a digital version or even a published copy.”
It follows a recommendation by the Reviewing Committee on the Export of Works of Art and Objects of Cultural Interest (RCEWA).
Member Peter Barber said: “The fragments under threat of export are particularly important.
“They show how Darwin revised his texts, pinning successive revisions onto sheets containing an earlier draft.”
The export licence application will be deferred until 7 May 2019 and could be extended if there is a serious intention to raise the money.