text: Addressing the issue of students getting value for money, he will challenge an "upward spiral" in university leaders' pay.
  Universities will be asked to publicly justify how they can pay their heads more than the prime minister.
  The question of university value has been under scrutiny, with fees increasing to £9,250 in England.
  In a speech to university leaders on Thursday, Mr Johnson will call for universities to set out much clearer contracts for students on what they can expect.
  He will promise better "consumer protection" for students.
  An annual study has shown a decreasing sense of value for money among students - with concerns about getting fewer teaching hours than they expected.
  Mr Johnson will highlight concerns over increases in vice-chancellors' pay - with dozens of university heads now receiving over £300,000 and some being paid more than £400,000.
  "When students and taxpayers invest so heavily in our higher education system, value for money should be guaranteed.  Yet, I am still hearing students say that their course is poor quality.
  "This is not good enough, especially when some vice-chancellors take home a wage that in some cases exceeds that of the prime minister."
  There have been concerns about the rising costs of university in England - with tuition fees increasing to £9,250 and interest rates on loans rising to 6.1%.
  The Institute for Fiscal Studies says that average debts for graduates will now be over £50,000 - and that interest charges will have reached £5,800 before students have even graduated.
  Former education minister Lord Adonis says such high levels of interest are "indefensible" and predicts that they will be changed.
  And the head of the Russell Group of leading universities has described such interest charges as "out of touch" and called for them to be reviewed.
  But Mr Johnson is expected to defend the current system of student finance and university funding.
target: Universities Minister Jo Johnson is going to challenge universities over "excessive" pay for vice-chancellors.