National teams could return to the Tour de France for the first time in 40 years as the event's organisers seek to change its image after another race beset by drugs scandals.

Patrice Clerc, the Tour's director, is considering a mixed format in future featuring national sides alongside the usual sponsored teams, something which has not happened since 1968.

"I believe a mixed formula is possible, not merely a proposition," Clerc told the Guardian. "Part of the teams invited to the event would be reserved for national squads. It is possible to envisage that and perhaps that is the road that we must go down."

Dave Brailsford, Great Britain's performance director, was supportive of the idea of entering a team in next year's Tour, saying: "Of course we'd do it if the situation arose, but it would depend on the ramifications in an Olympic year.

"If we were asked enter the Tour and it was politically and logistically feasible we'd do it."

National teams were part of the event from 1930 to 1961 and returned briefly in 1967 and 1968, after a strike over doping in 1966 prompted them to be brought back.

Clerc and his fellow organisers may now see the return of national teams as a way to edge out potentially suspect professional sides.

This year's Tour was won yesterday by Spain's Alberto Contador, but prior to that the event was tarnished by a positive drugs test for pre-race favourite Alexandre Vinokourov, the sacking of then Tour leader Michael Rasmussen by the Rabobank team over his conduct in missing a series of drugs tests and the withdrawal of the entire Cofidis team after their rider Cristian Moreni tested positive for testosterone.