"From a practical point of view, it's impossible and we have the feeling it would be inappropriate to hold a political summer camp on Utøya this year," the head of the Labour youth wing, Eskil Pedersen, told daily Verdens Gang.
On July 22nd, right-wing extremist Anders Behring Breivik, dressed as a police officer, spent more than an hour methodically shooting and killing 69 people, mainly teens, attending the camp on Utøya.
The small island, located some 40 kilometres north-west of Oslo, is currently in the process of being restored. Its dining hall, where many of the victims died, is set for demolition.
Immediately after the attack, Pedersen had vowed to "take back" the site and said new camps would be organised quickly, following a practice that dates back some 60 years.
"At the time it was difficult to gauge the amount of work and time needed in order to be able to reclaim possession of Utøya," Pedersen said on Wednesday.
"But our goal remains the same ... we will have summer camps there, but not this year," he said.
A ceremony marking the first anniversary of the attacks may however take place on the island on July 22nd, he said.
Just prior to his killing spree on Utøya, Behring Breivik, who has claimed to be on a crusade against multi-culturalism and the "Muslim invasion" of Europe, set off a car bomb outside government buildings in Oslo, killing eight people.
Behring Breivik's trial is due to start on April 16th.