Mr Miliband said the initiative was different from the government's Youth Contract in that it guaranteed a paid job on the minimum wage and on-the-job training, saying one of the government's work experience scheme was "the only work programme in history which does not guarantee work".
The new contract, which starts on 1 October, runs for a minimum of three years and could extend to seven as it has two separate two-year extension clauses written in to it.
However, agencies are asking supply teachers to sign a contract - known as a Swedish Derogation - to waive this right in exchange for continuous employment or a minimum payment if work is not available.