Formula One's governing body has stepped in to ensure McLaren give equal treatment to Fernando Alonso and Lewis Hamilton at the Brazilian Grand Prix.
Hamilton (l) is in his rookie season and up against the world champion
The FIA is appointing a special scrutineer for the race at Interlagos to ensure there is no favouritism.
That is despite McLaren's assurance the drivers would be treated the same.
Heading into the deciding race on 21 October Hamilton has a four-point lead over Alonso, who has become increasingly isolated within the team.
Alonso and McLaren boss Ron Dennis have had a very cool relationship following a series of rows.
The FIA's move comes after Spanish Motorsport Federation chief Carlos Gracia said he had spoken to FIA President Max Mosley about the issue.
"I showed my concern over the situation that Fernando is going through, which is no secret, and he [Mosley] reassured me," said Gracia.
"The FIA are going to have an official who is going to watch very closely that nothing bad happens to Fernando, above all in qualifying, which is where there have been most complaints or strange situations in recent races."
McLaren had already given an assurance that Alonso and Hamilton would be treated equally in Brazil.
"The team wants to make it clear its policy of treating both with complete equality and fairness will continue," a McLaren statement said.
"McLaren and Mercedes-Benz will continue to take every step that is within their control to ensure that both Fernando and Lewis will enjoy the same opportunity to win in terms of equality of car, engine, tactics and use of resources."
Alonso, who moved to McLaren at the end of last season after twice winning the drivers' title with Renault, has already said he believes the team have a preference for Hamilton.
Ferrari's Kimi Raikkonen is also in with a shout of the drivers' title.
The Finn is seven points behind Hamilton in the first three-way tussle for the championship since 1986.