Referee Jorge Larrionda of Uruguay gives the yellow card to Portugal's Cristiano Ronaldo during the 2010 World Cup Group G soccer match against Ivory Coast at Nelson Mandela Bay stadium in Port Elizabeth June 15, 2010. [Agencies]

PORT ELIZABETH, South Africa - Portugal have called on FIFA to overturn the yellow card issued to Cristiano Ronaldo during their 0-0 draw with Cote d'Ivoire in a World Cup Group G meeting in Port Elizabeth.

The Real Madrid star was booked in the 21st minute on Tuesday after tangling with Elephants right-back Guy Demel. Uruguayan referee Jorge Larrionda penalised both players in the incident, but now Carlos Queiroz's side has launched an appeal.

"The Portuguese player was tripped and pushed near the Ivory Coast penalty box. As soon as he got up, he was surrounded by his opponents and then pushed and insulted," the Portuguese Football Federation said in a statement.

"Given these facts, there is a disparity in the showing of the cards, once the African player, who committed a foul received a yellow card, and the Portuguese player who simply tried to walk away from the situation received the same punishment."

Television replays showed Ronaldo exchanging words with Demel and other players before being booked.

A further yellow card later in the tournament would see the former Manchester United ace serve a mandatory one-match suspension, unless Portugal's pleas are heeded.

Portugal's next test is Monday's Cape Town meeting with DPR Korea before they wrap up their group campaign against Brazil in Durban on Friday.