The 18-month collapse of devolved government in Northern Ireland is "not acceptable and cannot be allowed to continue", DUP leader Arlene Foster has said.
The former first minister spoke out after the Court of Appeal dismissed a bid by a Northern Ireland government department to have a High Court judgment over the powers of a civil servant overturned.
In May, a High Court judge ruled that a senior civil servant did not have the power to grant planning permission for a £240 million waste treatment centre and incinerator at Hightown Quarry in Mallusk.
The decision had been made by the permanent secretary of the Department for Infrastructure in the absence of a minister.
There have been no ministers in post in Northern Ireland since March 2 2017 following the collapse of the Assembly in January 2017.
Mrs Foster said the judgment "brings a sharp focus" on the absence of ministers in Northern Ireland.
"It is not acceptable and cannot be allowed to continue," she said.
"Key public services such as schools, hospitals and roads are being unfairly impacted."
She issued a fresh challenge to Sinn Fein to reach agreement with her party to restore devolution.
Mrs Foster added: "Four out of the five main parties would form an Executive today.
"In the absence of an Executive, decisions must be made in London.
"Last Friday, I welcomed the Government's statement that it would 'take whatever steps necessary to provide good governance'.
"I told the Prime Minister on Monday that it is now time to follow those words with actions.
"I welcomed the commitment from the Prime Minister that she is exploring a number of options."
Mrs Foster claims that Sinn Fein has refused to re-enter the Assembly, which has created a "backlog of decisions which require ministerial sign-off".
"Civil servants cannot be left in this limbo," she added.
However, Sinn Fein representatives have previously blamed the DUP for a failure to restore devolution.
Sinn Fein Northern Ireland leader Michelle O'Neill said in June that she believes devolution can be restored, but "only if there is political will there".
She insisted the reason for the failure "firmly falls at the feet of the DUP".