Great Britain's track and field team will not be allowed to attend the opening ceremony of the 2012 Olympics.
The London Games will open on Friday, 27 July, a week before the athletics event begins on 3 August.
UK Athletics head coach Charles van Commenee said: "It doesn't fit in the professional preparation for the biggest event of your life.
"In the end we are all aware that performance is number one. They can do the closing ceremonies."
The Dutchman believes that if athletes were forced to stand for long periods during the ceremony it may be detrimental to their chances of success, while some will still be at training camps at the time of the curtain raiser.
"They would not go shopping for eight hours before their biggest event so why would you be on your feet for that long?" he added.
"There will be a few at that time coming back from altitude and who will be based in Loughborough but you will not see track and field athletes on the 27th July in London."
British long jump record holder Chris Tomlinson said he would not be tempted to go the opening ceremony, preferring to focus on the build up to competition, but said it should be an athlete's choice whether or not to attend.
Tomlinson did not take part in the opening ceremonies in Athens in 2004 or Beijing in 2008, and said: "You've got to queue from the Olympic village many hours beforehand, and queue to wait to get on the buses."
"From start to finish it's at least a six to seven-hour event."
Van Commenee's decision also appears to rule out a member of the track and field team being chosen to carry the Union Flag into the stadium during the ceremony.
"Some are tempted because of the emotional, once-in-a-lifetime experience," said Van Commenee. "There has been a little noise, but they know it's not feasible."
The 57-year-old also drew a line under his dispute with Phillips Idowu.
Van Commenee was upset that the world triple jump champion withdrew from the European Team Championships on Twitter, but Idowu responded by saying he had gone through the official channels before posting the announcement on the social networking site.
"We have both decided to leave the incident behind us," van Commenee said.
"We have in common an important event this year [the World GB athletes to miss 2012 ceremonyChampionships in South Korea] and of course there is London the year after and that is what we focus on. We leave the rest that has happened behind us."
Van Commenee also confirmed that athletes will not be banned from using Twitter during the London Olympics.
"We're not going to do that," he said. "When you ban first of all you have to check and then you have to have sanctions otherwise it is pointless to ban anything.
"When we go to a championship we travel with more than 100 people, it is different to other sports. If you have to check all these people 24 hours a day that is an impossible task. We defer to common sense. We give guidelines and hope that they are mature enough.
"We don't have sanctions. Generally when you speak to athletes and give them advice with good reasons they usually follow that. They are mature people. I don't think sanctions are feasible or will prevent incidents from happening.
"We have planned a few athletes meetings and it is on the agenda to address the use of social media."
Idowu said that his row with Van Commenee would not prevent him from posting on Twitter during the 2012 Games.
"I haven't been warned off of it so I will see how the mood takes me," said the 32-year-old.
"If I have got something I want to share with my fans then I will.
"I am usually tweeting things which are quite positive and I would like to let people into the fun goings-on of the Olympic Village."