The Tory peer and former leader of Essex CC Lord Hanningfield (Con) will not go to the Supreme Court next month to argue that the criminal courts do not have jurisdiction to hear his case.
However, the three former Labour MPs facing criminal trials over expenses-fiddling allegations will do so.
Lord Judge, the Lord Chief Justice, refused permission to take the case to the Supreme Court in the wake of its dismissal, in July, of argument by David Chaytor, Elliot Morley and Jim Devine that they are protected from prosecution by parliamentary privilege.
But he gave them permission to pose a question to the Supreme Court Justices, allowing the three to make a direct application for a final hearing into the case.
Former Bury North MP Chaytor, 60, of Todmorden, West Yorkshire; ex-Scunthorpe MP Morley, 58, of Winterton, north Lincolnshire; and Devine, 57, of Bathgate, West Lothian, formerly MP for Livingston, are all on unconditional bail and due to face separate trials at Southwark Crown Court.
The Court of Appeal also ruled against Lord Hanningfield on the question of privilege but the Tory peer, who denies the charges, is not pursuing a Supreme Court challenge.