Former Prime Minister Gordon Brown said he would have been "laughed at" if he had acted like the current government during his tenure as Prime Minister.
In an interview on Good Morning Britain, the former Labour leader said the government needed to be upfront with the public.
He said: "In 2009 (during the global financial crisis), if I hadn't come on television and explained what was happening, I'd have been laughed at."
Co-host Piers Morgan said there was a sense the government was "passing the buck" by saying they were following the advice of science.
Mr Brown said: "If I had said in 2009 during the financial crisis, I was simply listening to the experts, people would have laughed at me and you've got to make your own decisions.
"You've got to get to the root of the problem."
He added he worries about a second wave and said the government must "ramp up testing".
Mr Brown also said: "We should admit mistakes and mistakes have been made" and added "you've got to be ahead of the curve, you've got to anticipate" what's happening.
The former Prime Minister said the government slogan shouldn't be "Stay Alert", but "Get Tested" instead.
He said: "If we are to prevent a second wave, if we're to get this R figure down, if we're to give people reassurance, then hand washing and social distancing is not enough.
"What we've got to do is test on a routine and regular basis all those people who are at risk... other members of the public should be offered a test.
"I would've said that instead of this slogan "Stay Alert", the slogan should be "Get Tested" and we should be providing the facilities for that to happen."
He added: "Boris Johnson should really come to the House of Commons tomorrow and make a statement about how he's going to ramp up testing" into the hundreds of thousands, "not a hundred thousand".
Mr Brown called for a summit between all the four nations of the country to work on ramping up testing together.
