A city councillor has failed in a bid to knock back an Adelaide Fringe request to close Rundle Rd for six weeks for next year's event.

Adelaide Fringe organisers have applied to Adelaide City Council to close Rundle Road in the East End from February 7 to March 21 next year.

The six-week closure will allow the expansion of the Garden of Unearthly Delights and Gluttony to include two new venues of 800 and 1000 seats that will spill onto Rundle Road.

Organisers say the new venues would host up to four shows a day for 28 days and improve disability access for the Fringe Corner Box Office.