LORD ISLINGTON had given Notice to move, That the Mandate for Palestine in its present form is inacceptable to this House, because it directly violates the pledges made by His Majesty’s Government to the people of Palestine in the Declaration of October, 1915, and again in the Declaration of November, 1918, and is, as at present framed, opposed to the sentiments and wishes of the great majority of the people of Palestine; that, therefore, its acceptance by the Council of the League of Nations should be postponed until such modifications have therein been effected as will comply with pledges given by His Majesty’s Government……
Britain’s Palestine policy was rejected 60 to 29 . Churchill then managed to get the Lords defeat reversed in the House of Commons where the Mandate was confirmed. See Mathew: Rescuing Balfour: Winston Churchill at the Colonial Office 1921-22
For a full transcript of the rest of the debate see Hansard.
See the article in the NY Times on the House of Lords debate on the Mandate 1922