Ofqual only received a single bid for the £13m contract to run controversial new pupil tests that will help set GCSE standards, TES can reveal.

In March, the National Foundation for Educational Research (NFER) was awarded a seven-year deal to develop and deliver new National Reference Tests (NRT) – designed to be used as independent measures to be used in deciding whether GCSE grades can go up.

But official documents reveal that by that stage there were no rival contenders.

Prominent assessment organisations including Pearson, Cambridge Assessment and Durham University’s Centre for Evaluation and Monitoring had all originally considered bidding.

TES understands that some of the concerns that led to them pulling out centred on the tight timescale for implementing the maths and English assessments.

Trials are due to start later this year, with the full introduction of the tests due from 2017. There were fears that the contract would “punish” a contractor that failed to set up the programme in “double-quick time”.

The mandatory tests will be taken by thousands of GCSE candidates in a sample of 300 secondaries every March.

If the scheme works as planned it would provide Ofqual, the qualifications regulator, and exam boards with the evidence they would need to allow GCSE grades to rise in future years.

But exam industry insiders have said they fear that Ofqual has not appreciated the technical difficulties involved. One told TES that it was reasonable to use a NRT to help monitor standards, but using it to set precise GCSE grade boundaries would not work.

In February researchers from Cambridge Assessment warned that the results will not be the “strong source of evidence for genuine changes in performance” in subjects other than maths and English, that the watchdog is hoping for.

Heads leaders have also said that schools will be “very anxious” about being forced to put year 11 pupils in for extra tests during the final run-up to crucial GCSEs.

Ofqual says that the tests should take less than an hour to complete and that results will not be published for individual pupils or schools.

A spokesman for the regulator said: “Ofqual followed a competitive tender procedure and several suppliers participated. Ofqual received one bid when tenders closed.”