A crackdown is needed on centres awarding English language qualifications to immigrants, the exams regulator said.

Ofqual said there were fears that some certificates were being issued with little or no training or learning taking place.

It has written an open letter to all organisations that award the English for Speakers of Other Languages (ESOL) qualification.

It said: “There are concerns being expressed about the way in which immigrants coming to the UK can obtain ESOL with citizenship qualifications, as a means to applying for permanent residence in the UK.

“Allegations are being made about a number of centres offering these qualifications, stating that the certificates are being issued with virtually no training or learning taking place and with insufficient rigour in the assessment process.

“We are writing now to ask you all to review your ESOL provision, to check the centres you have approved are offering this qualification without compromising its integrity, so that the learners get the qualification they deserve and certificates are therefore valid.

“Where there are cases of suspected malpractice at a centre we expect you as the awarding organisation to conduct a full investigation and take action as appropriate.”