A government department has been branded "shambolic" by MPs over its handling of a contract for court language services in England and Wales.
The Ministry of Justice ignored fears that standards would fall when the contract was outsourced, the Commons justice committee said.
Some interpreters failed to turn up, leading to cancelled trials, and others mistranslated evidence, it said.
Ministers said "dramatic improvements" had followed the initial problems.
The contract for language services began in early 2012.
The translation and interpreter services - for victims, witnesses and defendants - immediately ran into difficulties, MPs said.
The committee said the Ministry of Justice (MoJ) had not had a sufficient understanding of the complexities of court interpreting and translation work before it decided to put the services out to tender.
"The Ministry of Justice's handling of the outsourcing of court interpreting services has been nothing short of shambolic," committee chairman Sir Alan Beith said.
He said the MoJ "did not have an adequate understanding of the needs of courts, it failed to heed warnings from the professionals concerned and it did not put sufficient safeguards in place to prevent interruptions in the provision of quality interpreting services to courts".