Chancellor George Osborne has insisted security was his main concern as he considered a plea for an extra £200 million to combat terrorism in Northern Ireland.
Mr Osborne told the Commons "security comes first" as he assessed the call from Northern Ireland's Justice Minister David Ford.
The Chancellor said officials in the Treasury were performing "due diligence" checks on the request.
At Treasury questions in the Commons, shadow Northern Ireland minister Stephen Pound said: "You will be aware of the statement made by the Northern Ireland Justice Minister (on Monday). Can you explain the reason for the continued failure to make a decision?"
Mr Osborne told him: "It is a request I have taken very seriously. We are just interrogating the request properly."
Belfast East Alliance MP Naomi Long asked Mr Osborne to "confirm for the House that what has actually been requested by the Justice Minister in Northern Ireland is not additional funding but simply that the Treasury stand by the negotiated financial agreement that led to the devolution of policing and justice in the first place?"
The Chancellor told her: "We are carefully considering this request. I'm very clear that security comes first. Of course the Treasury has to do due diligence on any request from any department or from a devolved authority, but you should take it from me that we put security first."
Mr Ford had warned the entire architecture of devolution could face problems if the funding was not granted.
The Alliance Party MLA for South Antrim said: "If that were not made available, then the entire budget for the Department of Justice would be in major jeopardy and I believe it would be an indication of serious difficulty, frankly, for the entire process of the devolution of policing and justice."
The Police Service of Northern Ireland has been granted access to Treasury reserves over the last two years for funds specific to the terror threat. Last year the service drew down £50 million. Police chief constable Matt Baggott has asked for that access to be extended for the next four years, with an additional £200 million being made available.