Teams are on edge this week with growing uncertainty about who will be invited to the 2008 Tour de France.

Amaury Sports Organisation is heightening that anxiety ahead of Wednesday’s expected release of Paris-Nice invitations in what’s seen as the clearest signal for things to come ahead of the Tour.

ASO officials so far have remained mum, but there’s speculation that if teams are left out of next month’s Paris-Nice, they won’t be invited for the Tour. Participation in Paris-Nice, however, is no guarantee of a berth in the Tour as ASO still holds the cards when final invitations are issued in the coming weeks.

One sport director told VeloNews this week that the situation is “intolerable for the teams. Riders cannot plan their seasons. Sponsors cannot expect return on their investment. It’s bad for the image of cycling.”

Race organizers have resumed their powerful authority of arbitrarily inviting teams to their respective races following the rupture last fall with the ProTour, which guaranteed participation in cycling’s most important races for 20 top teams.

The ProTour has been reduced to 18 teams this season, but many of Europe’s most important races, such as the three grand tours and important one-day classics, have opted out of the league.

Last month, officials from the Giro d’Italia threw down the gauntlet by snubbing four ProTour teams - Astaná, High Road, Credit Agricole and Bouygues Telecom - for the season’s first major grand tour.

UCI president Pat McQuaid heavily criticized that decision, saying that cycling has taken “a step back 20 years.”

Tour director Christian Prudhomme told VeloNews that assuring a clean Tour is ASO’s “top priority,” adding that exclusions would include entire teams, not just individual riders with questionable reputations.

Some suggestions hitting the rumor mill are that any team with a hint of scandal from 2007 will not be welcome back to the Tour this year. That list is said to include Rabobank, Astaná, Cofidis, High Road (ex-T-Mobile) and Saunier Duval as well as Lampre and Liquigas.

Tour champion Alberto Contador said he is planning on defending his title and refuses to consider the prospect that Astaná might be left out of the season’s most important race.

“At the moment, I cannot imagine not going to the Tour,” Contador said earlier this week. “The (Astaná) team is completely new – new staff, new directors, new riders – the only thing that has stayed the same is the sponsor.”

The ambiguity prompted the professional cyclist’s association (CPA) to issue a communiqué stating that the insecurity is undermining team’s abilities to secure contracts with major sponsors.

“To weaken the teams by (leaving) a doubt as for their selection is not likely to attract the sponsors who … need to make their investments safe,” the communiqué read. “The foreseeable defection from important sponsors which were or will be not be invited to take part in the most (important) competitions will inevitably involve a job loss and unemployment as well for the riders as for the staff of several teams.”