Thirty lawmakers pedaled bicycles Friday around the Diet building in a public appeal for the Earth-friendly vehicles.
Construction Minister Katsutsugu Sekiya, Environment Agency chief Kenji Manabe and Labor Minister Akira Amari were among the lawmakers who participated in the rally.
The bikers started at the Education Ministry in the Kasumigaseki district and pedaled about 2 km to the main gate of the Diet via the Sakuradamon intersection.
The early morning cycling rally was sponsored by a suprapartisan league comprised of members of both houses of the Diet.
As part of efforts to curb global warming, the league was formed in February to promote the active use of bicycles as a way to reduce the consumption of fossil fuels, which have been blamed for global warming.
The league meets about once a month to discuss the issue and hold hearings, according to a secretary of Lower House member Takashi Kosugi, who heads the group.
The lawmakers were following examples set in the U.S. and Europe, where bikes are widely used, in a bid to promote policies to create more bike-friendly cities.