NI talks: Stormont talks at 'crucial stage'
Cross-party political talks in Northern Ireland resumed on Thursday.
The talks are aimed at resolving difficulties among the five parties in the devolved Stormont government.
On Wednesday, the chancellor said corporation tax could be devolved if politicians resolved their differences over the budget and welfare reform.
Northern Ireland Secretary Theresa Villiers said the negotiations over the next few days would be crucial.
"I think the credibility of the institutions are at stake here," she said.
"There is a real will out there, people want to see their politicians make it work.
"There is a recognition that we can't go on as we are, and also the reality that going into the next financial year with a deficit budget would lead to increasing chaos.
"The whole credibility of the institutions is at stake with these cross-party talks.
"It's vital that the parties are prepared to stretch themselves and prepared to make some awkward and difficult choices."
US envoy Gary Hart, who was due to attend the talks, stressed the need to reach agreement quickly.
In a statement issued on Wednesday night, he said: "The long-term public interest, including the interests of future generations, must be prioritised ahead of individual and party interests.
"This is a crucial moment and time is running out. A comprehensive settlement of these issues must be reached at the earliest possible date."
On Wednesday, Sinn Féin said it would not agree to the transfer of corporation tax to Northern Ireland "on the basis of implementing Tory policies".
First Minister Peter Robinson has blamed the delay in transferring powers on Sinn Féin and the SDLP's failure to agree a deal on welfare reform.
In his Autumn Statement to parliament, Mr Osborne said: "We recognise the strongly held arguments for devolving corporation tax setting powers to Northern Ireland.
"The Treasury believes it can be implemented, provided the Northern Ireland Executive can show that it is able to manage the financial implications. The current talks will see if that's the case.
"And if it is, the government will introduce legislation in this parliament."
The Northern Ireland inter-party talks are aimed at reaching agreement on a range of unresolved issues, including disputes over flags, parades, the legacy of the Troubles and welfare reform.
The five main parties have clashed over welfare reform in recent months, with Sinn Féin and the SDLP objecting to many of the cost-cutting measures that have already come into force in England and Wales.
Unionists have argued that Northern Ireland must take difficult decisions to balance its budget, but nationalist and republican MLAs have said that many of the reforms will disproportionately disadvantage some of the most vulnerable people in society.