<p><br /> David Cameron has stepped up demands for a "brief but comprehensive" inquiry into the Government lobbying row.<br /> </p><p><br /> The Tory leader insisted the case for a full investigation was "incredibly strong" after three former Cabinet ministers were suspended from the Parliamentary Labour Party on Monday night.<br /> </p><p><br /> Gordon Brown has dismissed the need for an inquiry after receiving assurances from Whitehall department heads that no improper influence was exerted.<br /> </p><p><br /> Ministers are seeking to distance the Government from the row which has engulfed Stephen Byers, Geoff Hoon and Patricia Hewitt, who are all facing allegations.<br /> </p><p><br /> The claims emerged in a Dispatches programme, aired by Channel 4 this week, in which they were interviewed by what they thought was an American lobbying firm.<br /> </p><p><br /> Justice Secretary Jack Straw said there was "anger" and "incredulity" among the MPs' Labour colleagues.<br /> </p><p><br /> But Mr Cameron said the row would further damage the public's faith in politicians in general, coming on the heels of the expenses scandal.<br /> </p><p><br /> "Our political system is looking evermore ragged and broken," he said.<br /> </p><p><br /> "Why? Because it depends on public trust and that trust has not just been damaged, it is in danger of disappearing altogether.<br /> </p><p><br /> "Every time we patch up one part of the broken politics another crack appears elsewhere."<br /> </p><p><br /> However, another MP featured in Monday night's Dispatches programme was a Tory backbencher, John Butterfill. He has referred himself to the Parliamentary Commissioner for Standards.<br /> </p><p><br /> Former Labour minister Baroness Morgan of Huyton, also facing claims, said she was referring herself to the House of Lords' Sub-committee on Lords' Interests.<br /> </p><p><br /> Backbench Labour MP Margaret Moran was also suspended after featuring in the programme.<br /> </p>
