Mr Muir was speaking after it was revealed that with no set budget agreed and in place, a top civil servant had been put in control of releasing funds to Ministers until an Executive could be formed.
He added: “This is yet another clear example of the damage the DUP’s current inaction is having on the people of Northern Ireland. We all deserve better.
“While this move is a necessary one, it is only a stop gap – with the longer our financial situation is allowed to limp along, the bigger implications we face down the line.
“Only a fully functioning Executive can start to relieve some of the suffering we are facing this winter. This will allow for a proper strategic, multi year budget to be put in place urgently. There is no escaping this is the only way we will move forward.
“With a massive cost of living crisis – which could see people having to choose between heating their home and feeding their families – not to mention pressures on public services and growing problems with the health service, it is long past the time the DUP can make their fall back excuses.
“Rather than work around problems, the DUP must recognise their only option is to allow an Executive to form as soon as possible. Their time is up.”