Just three out of 10 young Scots have claimed a free bus pass as part of the Scottish Government's flagship scheme.
Across Scotland just 284,328 children and young people aged between five and 21 have been issued with a pass, out of the 949,000 who are eligible.
That means uptake for the scheme - which opened for applications in January this year - is 30%.
The figures, obtained by Scottish Labour, have revealed.also showed that in 11 of Scotland's 32 local authority areas fewer than a fifth of under-22s had a pass - with just 13.3% of those eligible in South Lanarkshire having one.
Scottish Labour transport spokesman Neil Bibby insisted the "dire" figures were a "humiliation" for the SNP and Greens - who had both committed to bringing in the scheme as part of a Budget deal.
Mr Bibby said: "Free bus passes for young people should have been a good news story but these dire figures are a humiliation for the SNP and the Greens, who have spent years talking about this card but still failed miserably to deliver it.
"The botched scheme is a huge missed opportunity, which could have unlocked opportunities for children and young people, eased the cost-of-living crisis for families, and helped us tackle the climate emergency.
"Instead, the SNP's rampant incompetence has let a rare good news story descend into chaos - and it is young people who are paying the price."
He called on the Scottish Government to "streamline" the application process in order to "finally deliver on this years-old promise so that no more children and young people miss out".
However, a spokesperson for transport minister Jenny Gilruth said that Scotland was "in the grip" of the Omicron variant of covid when the scheme had launched and this had affected it.
The spokesperson said: "The Labour Party and Mr Bibby appear to have forgotten that in January of this year Scotland, like many other nations, was in the grip of the Omicron variant. Of course this impacted on the rollout of the under-22s scheme initially.
"Nevertheless, since the end of January, over six million journeys have been made and over 300,000 cards issued under the new scheme."
Ms Gilruth's spokesperson added that a "number of changes" had been made to the online application process, adding: "The transport minister has said that she will continue to monitor the situation and is not ruling out making further changes to the scheme if that is what is needed."
They continued: "Extending free bus travel to all of Scotland's children and young people under 22 is ultimately about making public transport more affordable, helping to improve access to education, leisure, and work, while supporting them to travel sustainably.
"While Labour carp from the sidelines, the Scottish Government is supporting people through the cost-of-living crisis. We are determined to ensure all children and young people who benefit most from free bus travel don't miss out."
