Boris Johnson has said it is "crazy" to use £9.3 million of taxpayers' money on a "very biased and hysterical" campaign about the risks of leaving the EU.
Responding to the news of the Government's pro-EU mailshot, Mr Johnson said both sides should have been able to put their arguments across.
He said: "Given that I think it's very likely that it will be very biased and hysterical and warning unnecessarily about the risks of leaving the EU, I think it's a complete waste of money.
"It's crazy to use quite so much taxpayers' money on stuff that is basically intended to scare people and to stampede people in one direction.
"I think what we want is a proper, informed debate and if you are going to use taxpayers' money, you should allow people to put the other side of the case as well."
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