Sleaze-busting MP Norman Baker is facing an investigation for adding fellow MPs' names to a House of Commons motion without their permission.

Speaker Michael Martin will personally investigate allegations the Lewes MP is guilty of a breach of parliamentary procedure.

The claim was made by Labour MP Bob Blizzard, who said his name had been added to an Early Day Motion on beer tax without his permission.

Mr Blizzard said the motion, which calls for the Government to slash the cost of a pint of beer by 30p if it is produced by a local brewery, contained "the names of a number of members who did not sign".

He told the Commons: "These members are seriously concerned some breach of procedure of the House may have been committed."

Mr Baker attempted to intervene, saying Mr Blizzard had not contacted him about the matter but Speaker Mr Martin interrupted to say he would investigate.

He would issue his ruling in the next few days.

Liberal Democrat Mr Baker, who famously helped bring down Cabinet minister Peter Mandelson over the Hinduja "cash for passports" affair, tabled the motion last week.

It called for the introduction of a "progressive beer tax" and attracted what appeared to be more than 100 signatures.

Mr Baker does not deny including the name of Mr Blizzard.

He explained the row by stating a motion on the need for such a tax had originally been tabled in 1997.

He wrote to every MP who had signed the motion, including Mr Blizzard, stating he was going to put down a new version.

The letter said if MPs did not wish to be included this time, they should write back.

Some MPs did so and were struck off but Mr Blizzard did not so his name was put down on the motion.

Labour MPs said Mr Baker's actions were "extremely unusual".

Some on the list held government posts, which prevented them from signing.

Hove MP Ivor Caplin, a government whip, said about 12 of his colleagues had complained.

He said they had expected Mr Baker to "behave better".

The tax is designed to help smaller breweries compete against drinks giants such as Carlsberg-Tetley, Whitbread and Bass.

Mr Baker wants to cut duty on ales produced by traditional breweries and remove it altogether from the UK's 300 micro-breweries.