Divisions between the DUP and Sinn Fein could disrupt efforts to deal with the economic crisis, it has been claimed.
SDLP deputy leader Patsy McGlone told his party's annual conference that the two political groups dominated the Assembly Executive, but had failed to reach agreement on key issues.
He told delegates that politicians now faced a tough test in grappling with the cuts imposed by Westminster.
"The Executive's immediate task is to agree a budget. It should already have been agreed," he said.
"The Draft Budget, as well as Savings Delivery Plans, should have been published by the end of October. Rather than focusing on that, we have seen party leaders grandstanding on their imaginary opposition to the budget.
"That is not good enough. And the people know it. But we know how well the two parties with a stranglehold on that Executive work together."
He added: "The danger of continued failure by Sinn Fein and the DUP should not be underestimated.
"In failing to agree a budget they are failing our future generations. Our children deserve better.
"We cannot afford the DUP and Sinn Fein's failed politics to be our society's future."
On dissident republican violence, he added: "There are those still wedded to the failed violence of the past. They haven't gone away either."