Labor bumped an announcement on Aboriginal health on Monday in Palmerston to announce it would also deliver the funding.
Opposition health spokeswoman Catherine King said that if Labor is elected, the scanner could be operational by the end of the year.
She said Ms Griggs had promised the scanner three times and failed to fulfil it.
Labor was in power from 2010 to 2013 but it didn’t fund the scanner; Lingiari MP Warren Snowdon said he never spoke to Ms Griggs about a bipartisan approach on delivering it.
‘This was a promise she made, not us,’ he said, adding that Labor had ‘other priorities’ in health at the time.
The scanner will allow Territorians with cancer to stay home and manage their illness rather than having to travel interstate for a cancer diagnosis.
‘This government has been appalling when it comes to health,’ Ms King said.
‘They have promised and promised and failed to deliver when it comes to the health of Territorians.’
She and Mr Snowdon denied the funding announcement was a decision made on the fly to score political points, saying Labor had been planning it for some time.