Andy Burnham has said the inquiry into contaminated blood took "far too long in coming".
Prime Minister Theresa May has ordered a public inquiry into the "appalling" incident, in which over 4,000 people with haemophilia became infected with HIV and Hepatis C after receiving blood transfusions with contaminated clotting factors.
The transfusions are believed to have occurred in the 1970s and the 1980s. Of more than 1,200 haemophiliacs infected, less than 250 people are thought to be alive in 2017.
With the announcement of the inquiry, the Mayor of Greater Manchester called for full cross-party disclosure once it gets underway.
He told Paul Ross: "This day took far too long in coming, the damage done in those decades was incalculable.
"It’s hard to feel any sense of triumph, this was a silent disaster affecting people over the course of many years.
"All political parties have let down the sufferers of contaminated blood. It’s incumbent on all of them to work together to make sure this new inquiry delivers truth and justice as soon as possible.
"That starts with full disclosure, there can’t be any papers held back."