The sharp rise in unemployment for those aged between 18 and 24 is concerning and shows younger workers are suffering, according to the national trade union.
Reductions in vacancies, a short period of time spent in work and the tendency to be employed on contracts are the main reasons, the Trades Union Congress (TUC) says.
According to the organisation, there was a 12.8 per cent quarterly increase in the three months to September in the number of young people unemployed for six months.
Nicola Smith, senior policy officer for economic and social affairs at the TUC, said at a time when employers are cutting back young people are likely to be asked to leave first.
"It might particularly be the case that sectors where young people do move into work have been relatively hard hit," she added.
The report by the organisation also showed there has been a 22.6 per cent quarterly increase in redundancies, with 156,000 people being asked to leave work in the three months up to September.