LANCE ARMSTRONG’S hopes of a seventh successive Tour de France victory received a significant boost yesterday when Jan Ullrich, his principal rival, postponed the start of his 2005 season until April because of what his T-Mobile team referred to as a lack of “basic stamina”.

That phrase may prove to be a euphemism for the return of the German rider’s well-documented weight problems, yet already Ullrich has given Armstrong a head start in his Tour build-up as the American will begin his pre-Tour campaign a month earlier at the Paris to Nice race on March 6.

Ullrich, 31, will not start his season as planned at the Tour of Murcia on March 2, but will instead enter a three-week long private training camp in Tuscany. A viral infection is also said to have set back his training programme at the beginning of February.

“For the time being it makes little sense for Jan to compete in such an intense race as the Tour of Murcia,” Lothar Heinrich, the T-Mobile team doctor, said. “Right now the focal point for him is on building up his basic stamina — which is the foundation for a successful season.” In recent years, Ullrich has struggled to shed the weight he habitually gains in the winter months as the Tour approaches, and his resumption of competition has often been delayed. His crash diets, coupled with intensive bouts of training, have become infamous in European cycling.

Last summer, Bjarne Riis, once the German’s team-mate but now director of the CSC team, questioned his professionalism. “Why isn’t Jan in shape in the spring?” Riis said. “Why is he constantly above his ideal weight? It’s beyond me.”

Ullrich’s season is now expected to start at the Circuit de la Sarthe in France in April. “The adjustment of his training programme doesn’t allow for a start at the Tour of Murcia, but we will work together for him to compete in good shape at the first races in April,” Rudy Pevenage, his coach, said.

In another development, Ivan Basso, the Italian rider who finished third overall in the 2004 Tour, was mourning the loss of his mother, Nives, who died yesterday after a long battle with stomach and liver cancer. The Italian revealed during the 2004 Tour that Armstrong, a former cancer sufferer, had used his influence to help Basso secure the best possible treatment for his mother.

While Basso, tipped as a contender for victory in both the Giro d’Italia and the Tour de France, struggles to overcome his bereavement, Armstrong’s pre-Tour schedule continues to take shape. His coach, Chris Carmichael, has also revealed the thinking behind the Tour champion’s decision to attempt a seventh successive victory.

“He realised that he was wondering, ‘I’m racing, training and the biggest race in the world is the Tour de France. Why don’t I just go back to it?’ ”, Carmichael said. “He never said he wasn’t going to race it. In every other year, he said he was. This year after winning, he said, ‘Well, I’ll do it again, but maybe I’ll take a bit of a break.’ He never said definitively. ”

However, Ullrich’s problems are unlikely to diminish Armstrong’s appetite for success. “He’s older, smarter, more experienced than everybody on how to win,” Carmichael said. “He’ll go there and say, ‘If I’m here, I’m not going to lose.’ ”

Armstrong’s pre-Tour programme will include Paris-Nice next month, the Tour of Flanders one-day classic in April and possibly the Dauphinée Libéré stage race in early June. He will also compete in the Tour of Georgia in the United States in late April.