Matt Hancock first raised public interest concerns over the acquisition last month – some weeks after the owner of the Daily Mirror agreed terms with Richard Desmond’s Northern & Shell group for the string of titles.
In addition to the dailies, the sale includes the Sunday Express, Daily Star Sunday and celebrity magazines OK!, New! and Star.
The announcement was made just 48 hours before Trinity Mirror shareholders are due to vote on a decision to rename the company Reach if the sale goes through.
The Government said the media regulator, Ofcom, would review public interest considerations – on top of the continuing Competition and Markets Authority’s (CMA’s) search for any competition issues.
Concerns include the possible reduction in the number of views in newspapers.
The two watchdogs have until 31 May to report back, after which Mr Hancock will decide whether to refer the takeover for an in-depth investigation or accept moves to address any concerns.
He told MPs: “I invited written representations from the parties by 26 April and, having considered these, I have written to the parties today confirming my decision to issue a Public Interest Intervention Notice.”
He added: “The role of the Secretary of State in this process is quasi-judicial and procedures are in place to ensure that I act independently and follow a process which is scrupulously fair and impartial.”
The announcement was made shortly after Mr Hancock confirmed he had received the CMA’s final report on the possible takeover of Sky – the owner of Sky News – by 21st Century Fox.
The secretary of state has until 13 June to consider the findings and announce his decision.