An application from TV presenter Chris Packham for a judicial review into the environmental damage caused by the controversial line was thrown out earlier this year.
But Lord Justice Lewison has now ordered an appeal hearing, saying the case was of "considerable public interest".
The second phase of the budget-busting line – which is expected to cost well over £100 billion – will carve through 45 miles of Staffordshire countryside on its way to the North West.
Judges will first examine whether Mr Packham has permission to appeal. If one is granted the court will then consider whether HS2’s approval should be subject to judicial review.
In February MPs voted to proceed with HS2 in full, with Boris Johnson describing it as the "spine" of Britain's new transport network.
But Mr Packham has argued that construction of the line will cause the irreversible destruction of ancient woodlands. He says the Government had based its decision to proceed on the Oakervee review, which had not sufficiently examined the environmental impact of the line.
He also said Ministers had failed to consider the implications of HS2 constructions emissions on the Paris Agreement, which requires a restriction on the global increase in temperature by 2050.
Mr Packham said: "I am delighted that the Lord Justices see merit in hearing the appeal and that they have acknowledged the ‘considerable public interest’ in the case – a public interest which spans the heinous and irreparable damage done to ancient woodland, breeding birds, badgers and bats this Spring, the complete incompatibility of this project to the Government’s obligations to address climate change, the appalling conduct of HS2 Ltd and its employees in a time of global crisis, and the future drain that the project will be on that public’s purse, which due to the pandemic is empty.
"The public have been conned by HS2, hopefully now we, the public, will see some justice."
Mr Packham's initial call for a judicial review was knocked back in April, with the DfT arguing that pausing the work would cost more than £20m.
The hearing is scheduled for July 8.
The DfT and HS2 Ltd have been contacted for comment.