MPs have sought an explanation from the Ministry of Justice over allegations that magistrates and court staff were instructed not to participate fully in an inquiry into the operation of a private sector contract to provide court interpreters.

In written evidence to the Commons Justice Committee, which is examining the contract with Capita, the chair of Peterborough Magistrates’ Court, Peter Beeke, said: ‘I receive a monthly report of [contractor] failures. Her Majesty’s Courts and Tribunal Service have specifically forbidden me from passing that data to this inquiry.’

Beeke said the initial service provided by Applied/Capita, which began the contract in February, was ‘truly catastrophic’. Beeke said the situation had improved, but that there are still cases where interpreters do not attend or are inadequate. ‘Of the figures I have seen and some anecdotal evidence, bearing in mind I am not allowed to quote precise detail, the numbers remain at an unacceptable level.’

A spokesman for the committee said its chair, Liberal Democrat Sir Alan Beith MP, has written to Helen Grant, the justice minister. Beith has also asked about allegations that court staff were instructed not to participate in an online forum set up by the committee to seek direct personal experiences.

The Ministry of Justice said Beeke would have been told not to disclose the data because the figures were not ‘validated and verified’ and thus not official.