Extra officials will be behind each goalline for Champions League matches and Euro 2012 qualifiers for the next two seasons, UEFA today announced.
The 'five officials' experiment follows the trial in the Europa League using the same system which has been proposed by UEFA president Michel Platini as an alternative to technology.
The International FA Board, the game's rule-making body, last week gave the green light to two more seasons of experiments and UEFA's executive committee decided to implement the trials in their showcase competitions.
Platini said last week: "The two additional referees will give more flow to the game.
"The arrival of TV has shown up referees' mistakes - the referee sees a lot but with an extra four eyes you will see more things and you help the referee to take a better decision.
"My problem as the originator of this idea and UEFA president and FIFA vice-president is that we have to cover all the parts of the field.
"That's why I have been fighting for this. TV cameras show all the mistakes in slow motion."
The FA, Premier League and Football League have said they are unlikely to experiment with the extra officials in any of their competitions.
However, former Premier League referee Graham Poll believes that UEFA's decision will not lead to a major improvement in the percentage of decisions officials will get right.
The use of additional officials was trialled in the Europa League this season with mixed results.
Poll, who is best remembered for famously awarding Croatia defender Josip Simunic three yellow cards before showing him a red at the 2006 World Cup, told Five Live: "I think there were moments where it (extra officials) worked well like when Dirk Kuyt scored a goal for Liverpool and the assistant tried to rule it out for offside, but the guy behind the goal knew that there had not been a touch.
"But I think there was a big mistake at Fulham where they tried to send off the wrong player with the help of the extra assistant and they made a mess of it.
"But you will always have human error, no matter how many officials you have that element will come in. We either embrace that and get on with it or we say we don't want that and we use the technological element."
Poll also believes it is time for the use of goalline technology or video replays to be trialled, and is disappointed that the game's governing bodies do not seem keen to implement such a system.
"What disappoints me is they are not prepared to try," he said.
"It is surely time to give it an opportunity. Try it in the something like the Carling Cup. If it disrupts the flow of play then they can say technology isn't helping, but if it makes it better it should be introduced.
"To say they will not even try to me is an error."
