The FIA has defended its decision to appoint Vitaly Petrov as a Formula 1 steward in Portugal this weekend.

Six-time world champion Lewis Hamilton hit out at the decision, having been criticised by former F1 driver Petrov over his political activism including kneeling and wearing Black Lives Matter-themed t-shirts on the podium.

"Let's say a driver admits to being gay - will they come out with a rainbow flag and urge everyone to become gay as well?" Petrov had told Russia's Championat last month.

"I think the FIA will no longer allow such behaviours."

Hamilton's podium activism was indeed stopped by the FIA, but the world championship leader said he was nonetheless surprised by the appointment of Petrov as steward.

"It is a surprise to see that they are hiring someone who has those beliefs and is so vocal about things we are trying to fight against," he said.

"So I don't quite understand what the FIA's goal is or why particularly he is here because it is not like they don't have other options."

Hamilton's Mercedes teammate Valtteri Bottas agreed that everyone in Formula 1 "should have the same mindset for the things we are pushing on".

But the FIA defended its call, insisting that the governing body "will not discriminate on the basis of views expressed outside of their functions as an FIA steward, provided that any such expression does not contradict the rules and code of ethics of the FIA".

Sky Italia asked FIA president Jean Todt about Hamilton's activism, and he answered: "I respect anyone who wants to fight.

"The important thing is to do it in the right way and at the right times. It's like driving a car at the limit," Todt added.