The motion would ask for the transport secretary's salary to be reduced - a Commons technicality - and will be debated within the next 10 days even if Mr Blair refuses to allow it to replace a scheduled debate on the modernisation of Parliament.
In their never-ending quest for new marketing sites, advertisers have added branding to public transport turnstiles, food cartons, supermarket eggs, and even airline motion sickness bags.
Earlier this year, the assembly backed a motion expressing concern at the "poor state" of the public transport system and seeking a comprehensive and integrated policy to be implemented.