Former Lions lock Nigel Horton has dubbed aspects of the 2005 squad's training in New Zealand as "pathetic".
Horton: Lions training was "pathetic"
Horton attended Lions training sessions as a representative of Predator, the team's training equipment manufacturer.
"The system was designed to give each coach equal time with the players," he told the Sunday Times.
"Andy Robinson had only 20 minutes to spend on scrums, line-outs, rucking and mauling. That's pathetic for a side hoping to compete with the All Blacks."
Horton played on the 1977 tour of New Zealand and won 20 England caps between 1969 and 1980.
He revealed how the 2005 Lions' training consisted of 100-minute sessions, split into 20-minute blocks of a warm-up, defence, forwards and backs, before the players came together for the last 20 minutes.
Horton, who operated the scrum-machine during training, was scathing about the Lions set-piece work.
"I wasn't surprised the pack made no impact on the All Blacks," he added.
"In South Africa in 1997 I told Fran Cotton that the Lions needed to spend more time scrummaging before the first Test and Jim Telfer gave them a two-hour beasting - that's close to 100 scrums.
"The maximum they put down in New Zealand was 16. Not one of the them was opposed - and they didn't practise a single back-row move."
He was also unimpressed by the Lions line-out, which fell apart in the first Test as New Zealand plundered 10 of their throws.
"Schoolboys know you don't throw to the back in gale-force conditions," he added.
"Schoolboys also know you keep it tight against the wind and kick with it, yet the Lions did neither.
"When I asked afterwards, I was told that the weather conditions weren't even discussed at half-time."