Ministers have denied claims that the introduction of a new Sentencing Council is intended to drive down prison numbers.
The claims were sparked by a Ministry of Justice document which suggested that the establishment of the council could halt an "upward sentencing drift" which had seen courts impose tougher penalties on offenders.
Closer adherence to the council's guidelines on punishments could avoid the need to build 1,000 additional prison places, the document suggested.
The new Sentencing Council will replace the Sentencing Guidelines Council and Sentencing Advisory Panel when it comes into effect in April.
Legislation states that courts "must follow its guidelines" where they only had to "have regard" to the recommendations of the previous bodies.
The Daily Telegraph quoted an MoJ "impact assessment" on the new body, which said: "Closer adherence to sentencing ranges could arrest historical trends in upward sentencing drift.
"Arresting sentencing drift could potentially mean avoiding the need to build some 1,000 additional prison places."
Shadow justice secretary Dominic Grieve said it was important that sentences were not "driven by the Government's failure to provide enough prison places".
But prisons minister Maria Eagle said: "It is entirely untrue to suggest the Sentencing Council is a back-door way of reducing prison population.
"Indeed, the council was supported by politicians on all sides in order to better predict the size of the prison population, not to manipulate it."