The campaign would build on controversial press ads launched earlier this month by Is, a subsidiary of M&C Saatchi.
The ads targeted commuter town Staines, home to the fictional Ali G, as a good reason to leave Britain for Adelaide and included the strapline: "Screw working in Staines, hello Adelaide."
Bill Muirhead, a partner of M&C Saatchi, said in an email to Baron Cohen's representatives that the agency had an idea for a TV and cinema ad that takes a cheeky dig at some of the less attractive features of life in the UK.
Muirhead said: "Things like housing prices, traffic congestion and dreary, boring place like Bromley, Croydon, Slough and Staines.
"We would like to use the Ali G character to front the campaign to represent the core values of the town of his birth."
Muirhead said that the aim of the campaign, for the South Australian Tourism Commission, is to fill a skills shortage in more than 65 categories and professions in Adelaide, by attracting migrants and tourists.
Baron Cohen, who is married to Australian actress Isla Fisher, has previously said that his Ali G and Borat characters have retired.
If Ali G fails to come around, there are the options of Staines other cultural exports, which include indie band Hard-Fi and comedian Bobby Davro.