Fresh concern has been raised about the Youth Justice Board's strategy to reduce the number of beds contracted from local authority secure children's homes (Laschs).

It comes just days before one of the two remaining homes in London, Stamford House, was due to close after the Youth Justice Board decided not to renew its contract.

The YJB wants to reduce beds in secure homes, while increasing the number in privately run secure training centres (STCs), which it believes are more cost-effective.

But Enver Solomon, principal policy officer at the Prison Reform Trust, said STCs cost less to run because staff were paid less and worked in inferior conditions.

As a result, STCs attracted "a lot of inexperienced staff" who were not used to dealing with the challenging behaviour posed by young offenders, he warned. This has led to high staff turnover rates.

Solomon said the STCs were also "far too large to deal with youngsters with such complicated needs".

Angus Mackay, project director of London Secure Services, said Laschs could attract a better calibre of staff because they offered higher salaries. He said most appointments involved trained staff with at least two years' experience in managing people with challenging behaviour.

A YJB spokesperson insisted that, although the cost-effectiveness of STCs was a consideration, it was not the only reason for the decision to increase their number of places. Whereas Laschs take children on welfare grounds as well, STCs are intended for young offenders only.

She said variations in staff pay were the result of different geographical areas and local authority pay scales. Although the social work experience among STC staff varied, they would all undergo intensive training before they started.