Three former Labour MPs and a Tory peer will stand trial in a criminal court accused of fiddling their expenses, a judge ruled today.

The criminal courts have the power to try the four men and they are not protected from prosecution in the crown courts by Parliamentary privilege, Mr Justice Saunders told Southwark Crown Court in central London.

Former Labour MPs David Chaytor, Elliot Morley, and Jim Devine, and Tory peer Lord Hanningfield, also known as Paul White, are accused of theft by false accounting.

Former Bury North MP Chaytor, 60, of Todmorden, Lancashire, is accused of falsely claiming rent on a London flat he owned, falsely filing invoices for IT work and renting a property from his mother, against regulations.

Former Scunthorpe MP Morley, 57, of Winterton, North Lincolnshire, is charged with falsely claiming £30,428 in interest payments between 2004 and 2007 towards a mortgage on his home which he had already paid off.

Former Livingston MP Devine, 57, of Bathgate, West Lothian, is accused of wrongly submitting two invoices worth a total of £5,505 for services provided by Armstrong Printing Limited.

He also faces a second charge alleging that he dishonestly claimed cleaning and maintenance costs of £3,240 by submitting false invoices from Tom O'Donnell Hygiene and Cleaning Services.

And former Essex County Council leader Lord Hanningfield, 69, of West Hanningfield, near Chelmsford, Essex, faces six charges of making dishonest claims for travelling allowances.

All four defendants are on unconditional bail.

Mr Justice Saunders said: "I can see no logical, practical or moral justification for a claim for expenses being covered by privilege; and I can see no legal justification for it either.

"In my judgment, the conduct alleged against these defendants is not covered by Parliamentary privilege and is triable in the Crown Court.

"Unless this decision is reversed on appeal, it clears the way for what most people accused of criminal behaviour would wish for: a fair trial before an impartial jury."

He granted all four defendants, who were excused from attending today's hour-long hearing, leave to appeal.

The argument that submitting an expenses form was part of the proceedings of Parliament, and therefore protected by Parliamentary privilege, was akin to saying that the coin used in a slot machine was part of its machinery, Mr Justice Saunders said.

"The decision that I have had to make has not been easy," he said.

"If the question of Parliamentary privilege had not been raised, I would have initiated this inquiry myself, as I would have had to satisfy myself that the allegations to be investigated at trial were not covered by privilege."

He added that the privilege was that of Parliament, and not of any individual member, so the defendants would not have been able to waive it even if they had wanted to.

"Comments in the media and from prominent politicians to the effect that they could were misconceived," he said.

"It follows that the even more extreme suggestion in some quarters that the fact that the defendants have raised this issue is some indication of guilt is not only misconceived but also unfair."

He went on: "Very important constitutional principles are involved which must be respected, and that must be the case even if it leads to a result which is unpopular not only with the public but also with Members of Parliament."