A Home Office minister who demanded to know whether senior probation officials backed or opposed a keynote policy did not act improperly, a spokeswoman has insisted.
Gerry Sutcliffe, according to an email seen by the Sunday Times, asked for a list of "positive champions, more negative chiefs and those who were broadly neutral".
It was sent by his private secretary as the minister faced a potential rebellion by Labour backbench MPs over controversial plans to increase the role of the private sector in the service.
Shadow home secretary David Davis told the paper it was "entirely improper" to seek out civil servants to be used to promote a government policy to MPs.
"Even more improper is drawing up a list of people who oppose your policy. One can think of no other reason to do this than to punish them or gag them in some way," he said.
But the Home Office insisted: "There is no question the minister acted improperly or sought to undermine the political impartiality of his private office.
"It is normal that the opinions of stakeholders are canvassed and assessed before a Bill is published as often they are on the front line delivering the policies.
"It is also normal to identify those supporting voices for proposed legislation."
