Scottish Labour leader Anas Sarwar said Ms Sturgeon had previously failed to deliver fast track diagnostic centres and had now “re-promised” them as part of the election campaign.
The SNP leader on Monday had announced that if re-elected she would “aim to pilot three fast track cancer diagnostic centres from this summer” with a £3 million investment, which would be “followed by full roll-out to every health board area by the end of the Parliament”.
However, the Scottish Government promised in December two early cancer diagnosis centres would have opened “by spring”.
Mr Sarwar said: "Failures have consequences, in this case devastating ones.
"I have been pressing Nicola Sturgeon on this for years. Promises were made to deliver these services – the failure to do that has put lives at risk.
"It is shameful for the SNP to attempt to pledge at an election what they have failed to deliver in government.”
Breast, cervical and bowel screenings were stopped between March and July during the first Covid lockdown and charities have warned of a cancer time bomb as a result, and urged the opening of fast-track diagnostic centres.
Mr Sarwar had also previously raised the issue of missed and delayed tests at First Minister’s Questions, when he claimed almost 45,000 people were waiting more than the six-week target for diagnostic tests.
He called for a full restart of cancer services in Scotland following statistics that show 7,000 fewer people had a confirmed cancer diagnosis in the first eight months of the pandemic compared to expected numbers.
Mr Sarwar said: "They have been in power for 14 years. The First Minister has been in post for seven years.
"Experts estimate that 7,000 Scots are living with undiagnosed cancer because of the disruption of the pandemic. That is a record of shame and, frankly, Scotland deserves better.
“At a time when we should be focusing on what unites us, not what divides us, it is unfortunate that the First Minister is putting her party's campaign before the national interest."
Scottish Liberal Democrat leader Willie Rennie also criticised Ms Sturgeon’s announcement.
“The government should have acted months ago rather than holding investment back until election time,” he said.
"That’s holding people’s health to ransom.”
The SNP said Ms Sturgeon’s announcement was the first in a series of pledges in the election campaign “designed to help the NHS recover from the most challenging period in its history – with a package of major investment in NHS staff and its resources, and reform in the way health and social care is delivered”.
In her campaign speech, she said: “I can announce today that as part of our cancer recovery plan, a re-elected SNP Government will establish at least one new fast-track cancer diagnostic centre in every health board area.”
The first two centres at Crosshouse Hospital in Kilmarnock, and Dumfries and Galloway Royal Infirmary are currently advertising for staff.