This is a muddy claim. What is "government policy"? How many top leaders must know about it? Who must decided it, so that it becomes "government policy"?
It is highly debated, inconclusively, if Hitler ever gave such command. First it was claimed that it was proven in writing, but this is not on the table any more (except, I guess, with some posters here, like the one who still claims 4 million vistims in Auschwitz). But is that decisive regarding "government policy"? Add to that, that Hitler's recorded statements are often contradicting; how do we know, when he was lying and when he changed his mind? And does that matter?
Himmler's "Posen speeches" were very explicite (some are disputing that too). If only Himmler had given the commands, was that government policy or not?
To make it even muddier, the "government policy", whatever that is, was not constant. Supporting immigration in Palestinia and enforcing settlement in Madagaskar were different from deportation in the occupied Soviet regions, the latter meaning death with high probability.
The part exterminating a complete people is even more of a problem. If that was really a policy, then why have been hundreds of thousands kept in those camp, where no mass killing took place? And no, not only those were there, who were needed for their labour.
All in all, I would drop the "government policy" claim, no matter which side one defends or disputes.
In effect, this is the old claim of Irving's that "Hitler didn't order the Final Solution", isn't it?
Let's focus on one seminal point - the Wannseekonferenz. Reichsmarschall Göring - Hitler's designated successor - ordered Heydrich to organize the Endlösung and to co-ordinate the participation of all government agencies involved.
Who were present at the Wannseekonferenz, apart from Heydrich himself? Look at the
minutes:
Gauleiter Dr. Meyer and Reichsamtleiter Dr. Leibbrandt -
Reich Ministry for the Occupied Eastern territories
Secretary of State Dr. Stuckart - Reich Ministry for the Interior
Secretary of State Neumann - Plenipotentiary for the Four Year Plan
Secretary of State Dr. Freisler - Reich Ministry of Justice
Secretary of State Dr. Bühler - Office of the Government General
Under Secretary of State Foreign Office - Dr. Luther
SS-Oberführer Klopfer - Party Chancellery
Ministerialdirektor Kritzinger - Reich Chancellery
SS-Gruppenführer Hofmann - Race and Settlement Main Office
SS-Gruppenführer Müller, SS-Obersturmbannführer Eichmann - Reich Main Security Office
SS-Oberführer Dr. Schöngarth, Commander of the Security Police and the SD in the Government General - Security Police and SD
SS-Sturmbannführer Dr. Lange, Commander of the Security Police and the SD for the General-District Latvia, as deputy of the Commander of the Security Police and the SD for the Reich Commissariat "Eastland" - Security Police and SD
That's pretty much your whole Nazi government and party apparatus involved. And all these ministries and agencies were invited at that high level because their cooperation for the Endlösung was needed. No, trying to say "it wasn't government policy" is as hypocritical as saying "ich habe es nicht gewusst".