The home secretary has come under fire for suggesting that the name of the Crown Prosecution Service will be changed.

In an urgent question in the Commons, shadow attorney general Dominic Grieve questioned why David Blunkett had suggested that the CPS should be renamed the Public Prosecution Service.

Speaking on Tuesday, Blunkett said that "right across the country, the CPS will become the Public Prosecution Service and will become much closer to being understandable by the public".

However, that comment appeared to go further than the government's official policy, which is to say that the name change is under review.

Grieve said the issue was not the home secretary's departmental responsibility.

He said the Home Office "should have no departmental role in the operation of the Crown Prosecution Service or the judiciary because of the risk of political interference".

The Conservative spokesman said the principle that the crown was nominally responsible for prosecutions and justice should be preserved.

"The problem with all these proposals is that they risk undermining the independence of the judicial system and the administration of justice, they undermine the crown in its central role of ensuring the non-politicisation of the system of justice, and in the process they undermine our freedoms," he added.

Responding for the government, solicitor general Harriet Harman said the government was determined to ensure a "partnership" in the administration of justice.

"There is no risk of politicisation of the Crown Prosecution Service," she added.

Defending Blunkett's comments, Harman said he was simply answering a question he had been asked.

"He was asked a question which actually relates to an issue on which the attorney [general] has the lead.  He was quite right to answer it, it would have looked very odd if he hadn't have done."

For the Liberal Democrats, constitutional affairs spokesman David Heath said that Blunkett had wrongly spoken out on an issue that was "simply not a matter" for him.

He said the muddle showed the need to establish a separate Department of Justice to oversee the legal system.