The justice secretary must resign if he cannot reverse low conviction rates for rape within a year, Labour has said.
Shadow justice secretary David Lammy said Robert Buckland shed "crocodile tears" when he apologised for convictions falling to a record low.
A government report this week said only 3% of reported rapes in England and Wales resulted in a prosecution in 2019-20 - down from 13% five years ago.
Mr Buckland said Mr Lammy's comments had no place in a serious debate.
The justice secretary told the BBC's Andrew Marr Show that Labour was pursuing "low politics" in challenging him to improve the conviction rates or resign.
He said: "It is constitutionally illiterate to suggest that a politician like me should in any way command and control the way that independent police and prosecutors go about their work."
Of course it is constitutionally illiterate, Lammy is speaking on behalf of a constitutionally illiterate party. Not that the Tories are much better. The figures are interesting though. I don't know how Lammy would increase the number of charges, let alone convictions. Maybe he he doesn't either.
3% charged - but convictions too low according to Lammy.
11% no suspect identified - but pursue the case anyway?
27% evidential difficulties - so fudge the evidence?
57% victim withdrew the allegation - but pursue it anyway?
2% other outcomes.