The DUP deputy leader has said he wants direct-rule ministers running NI "within weeks" if an agreement cannot be reached to restore power-sharing.
Nigel Dodds said ministers from London could make decisions in conjunction with the parties at Stormont.
He told the BBC he was "optimistic" a deal could be done between the DUP and Sinn Féin but key decisions on public services needed to be made.
Northern Ireland has been without a power-sharing executive since January.
The Democratic Unionist Party (DUP) and Sinn Féin have failed to reach an agreement in spite of numerous rounds of discussions since assembly elections in March.
After the latest deadline passed without a deal, Northern Ireland Secretary James Brokenshire laid out his plans for a budget to MPs on Thursday.
However, he was adamant it did not mean a return to direct rule from Westminster.
Speaking on Radio Ulster's Inside Politics show, Mr Dodds said: "I have made it very clear we can only go on in this semi-direct rule in certain areas, welfare and now the budget, for a very short period.
"We need decisions to be taken by ministers and if those aren't going to be Northern Ireland Executive ministers, then I think within a few short weeks we need to move to an appointment of direct-rule ministers.
"You can give civil servants the power to spend money, but there are a lot of decisions stacking up and you have to have ministers to make decisions."
When asked if he thought Sinn Féin could walk away from the process if direct-rule ministers were brought in, he said: "The alternative is that we end up with no ministers making any decisions until Sinn Féin come to their senses.
"So, what happens to public services in the meantime? We can't have the current limbo."
'I believe so'
The North Belfast MP also said he was appalled by the allegations of sexual assault and harassment at Westminster, describing them as "horrific".
He added he would be meeting Prime Minister Theresa May with the other parties on Monday to agree a process for people to report allegations.
Asked if the DUP record at Westminster was clear he said: "I believe so."
The Northern Ireland Executive collapsed in January amid a bitter split over the handling of a botched renewable energy scheme.
Sinn Féin's demand for legislation to give official status to the Irish language has become one of the main stumbling blocks in negotiations to restore the executive.