Speaking to The Independent, Steve Barclay MP said he would be demanding answers for the family of Jasmine Hughes, who died at the hospital in 2011.
Mr Barclay, who is chief secretary to the Treasury, wrote to Matt Hancock on behalf of Jasmine’s parents, as their constituency MP, after The Independent revealed new evidence of possible failings in her care by the world famous children’s hospital.
Medical experts who examined detailed computer records believe that Jasmine’s dangerously high blood pressure was mismanaged, causing her to develop severe brain damage.
Great Ormond Street Hospital has admitted that crucial medical evidence about Jasmine’s condition when she arrived at the hospital’s intensive care unit was not provided to a coroner’s inquest.
Key clinical events in Jasmine’s care do not feature in her medical records and some notes have gone missing.
Great Ormond Street Hospital has denied any intention to cover up what happened to Jasmine and has apologised for evidence not being shared with the coroner.
Mr Barclay, a former health minister, said he was “deeply concerned” by the case and revealed he had also written to the attorney general, Suella Braverman, ahead of a request by the family for a new inquest.
He has also asked the Parliamentary and Health Service Ombudsman to consider an investigation.
He told The Independent: “I have escalated this to senior levels within government. It is clear to me as the family’s constituency MP that this wasn’t getting the level of attention it warranted from Great Ormond Street.
“The current position is deeply unsatisfactory and simply cannot be left in its current state. As their MP I want answers and I will be demanding answers for the family. After such a tragic loss, the least that should be done is full transparency.”
Mr Barclay said he felt the case had similar elements to past scandals he was familiar with in the NHS while serving as a health minister, adding: “I am deeply concerned.”
He said he believed that the case for an investigation by the health ombudsman was beyond question: “Let me be clear: I expect them to do so.”
After reading of the case in The Independent last week, Mr Barclay said: “I raised the case with Matt Hancock for a deep-dive review into how this chain of events has happened and where accountability needs to apply, after due process, for those found responsible and what wider lessons can be learned.”
“I want to ensure no stone is left unturned. The family have the right to the truth and there are serious concerns as to whether they have had the full truth regarding such a heartbreaking tragedy.”
Jasmine’s parents, Jeff and Joanne Hughes, from Doddington, near Cambridge, have been fighting for almost 10 years to get to the truth of what happened to their daughter.
Her mother told The Independent she was pleased Mr Barclay had taken up the case with the health secretary.
She said: “I think a wider inquiry is needed into the way GOSH has responded, not just in our daughter’s case but in many other cases. I don’t believe what happened to us is an isolated incident.
“It seems to me that there is a pattern of failing to investigate incidents and not sharing information externally with families.
“There is plenty of evidence of families and the hospital’s own staff raising concerns about the safety culture and transparency at Great Ormond Street and now is the time for the wider investigation.”
Jasmine’s parents are now planning to apply to the attorney general to ask for the inquest verdict into Jasmine’s death be overturned and a new inquest to be held, in light of details not being shared with the coroners.
Ms Hughes said: “I want an inquest where independent opinion is considered and all available evidence is included for review, neither of which happened last time.
“It is crucial to me as a mother that Jasmine has a death certificate that reflects the truth about why she died. As a family we deserve that.”
A spokesperson for Great Ormond Street Hospital said: "We always seek to be open and transparent and welcome any investigation that would be helpful to Jasmine's family in addressing unanswered questions they may have. Further investigation could add to the number of reviews into this case that have already been carried out, both within the hospital and involving independent external bodies."