Former health secretary Andy Burnham has faced criticism for blocking a public inquiry into regulatory failings within the NHS.
Campaigner Julie Bailey said Mr Burnham had frustrated attempts for a full inquiry and instead wasted public money by setting up a smaller and more limited investigation following the scandal at Mid Staffordshire NHS Foundation Trust.
She said: "We knew people were dying throughout the NHS. It was not just Mid Staffs. We continually told the Labour government, we followed ministers all over the country, we stood outside their constituencies throughout the winter."
Appearing before peers examining the way the Inquiries Act works, Ms Bailey said it was only the change of government in 2010 that led to a public inquiry.
Ms Bailey, who founded the Cure The NHS group after her mother Bella died at Staffordshire General Hospital in 2007, said ministers should be stripped of the power to decide whether or not to hold a public inquiry because of the potential conflict of interest.
She told the Lords committee: "There should be some formula that says if there's such a disaster, this is the criteria you can use for a public inquiry.
"We gave up two years of our lives to follow ministers all around the country. That's not easy to do and people don't do it normally but we were determined because we had lost in such a way we wanted other people not to suffer.
"That's not right, we shouldn't have had to have done that. There was no way we were going to get a public inquiry unless there was a change of government.
"That's the only reason we got a public inquiry. We could have followed the Labour government all over the country for 20 years, we wouldn't have got the public inquiry because it wasn't in their interest to give it to us."
A Healthcare Commission report into the Mid Staffs failings in 2009 was followed by an "independent inquiry" set up by Mr Burnham, led by Robert Francis QC.
When the coalition Government took office, Mr Francis was asked to chair a full public inquiry looking at the regulatory failings, and he published a damning report in February this year.
Ms Bailey said the first investigation led by Mr Francis was unnecessary and was motivated by Mr Burnham's desire to stop a judicial review of the decision not to hold a public inquiry.
She said: "I didn't want the independent inquiry. We had followed ministers all over the country by the time we had got the independent inquiry (asking) for a public inquiry.
"I went home the night of the Healthcare Commission report to hundreds of emails. I knew this was a national problem, it wasn't confined to Mid Staffs and it certainly wasn't an isolated case, which is what the Labour government was trying to tell us it was.
"The independent inquiry was decided by Andy Burnham. What he said he wanted to do was to look at the hospital. What we continually told him was that the Healthcare Commission report was an adequate report into what had gone on at the hospital, we now needed to look at the regulatory bodies and that's exactly what the Mid Staffs public inquiry did.
"What I learned from evidence to the Mid Staffs public inquiry was we were given the independent public inquiry, what we had done was we had tried a judicial review... and what the independent inquiry did, by giving it to us, it stopped our judicial review.
"That's why we were given the independent inquiry."
She said the publication of the Keogh review this year into high death rates at hospitals illustrated the need for the wider inquiry she had demanded.
"The Keogh reviews which have come out this year was evidence," she said. "Those hospitals reviewed in the last year, those emails came through to me in 2009 when the Healthcare Commission report came out.
"That's why we were determined that we had to have a public inquiry because people were suffering. It was no good examining the hospital again, it had already been examined, it needed to move forward.
"That's precisely what Andy Burnham was telling us - that the hospital needed to move forward, we didn't need the public inquiry. But by giving us the independent inquiry into the hospital that's precisely what it was doing, it was holding the hospital back."
She added: " We didn't need the non-statutory inquiry. It was a waste of public money. We should have gone straight for the public inquiry, the statutory inquiry."