The conservative group Club for Growth said Wednesday that a Republican House budget plan authored by Rep. Paul Ryan (Wis.) is a “disappointment” to fiscal conservatives that falls short of making necessary cuts to balance the nation’s budget.

The group’s president said in a statement that Ryan’s plan does not put the country on a path to chop deficits quickly enough.

Chris Chocola also complained that that the budget largely waives massive cuts that are set to go into effect in January as a consequence for the failure of Congress’s special deficit reduction “supercommittee.”

According to the Budget Control Act — the hard-fought law that raised the nation’s debt ceiling over the summer -- failure of the supercommittee was to trigger about $1.2 trillion in cuts over the next decade, split between military and domestic spending.

In Ryan’s budget, the so-called sequester--deeply unpopular to Republicans because of its powerful hit to defense--would be replaced. Tackling only the first year of the cuts—about $110 billion—his budget calls for instructing Congressional committees to come up with $18 billion in trims the first year and $116 billion over five years.

“It is hard to have confidence that our long-term fiscal challenges will be met responsibly when the same Congress that passed the Budget Control Act wants to ignore it less than one year later. On balance, the Ryan Budget is a disappointment for fiscal conservatives,” Chocola said in a statement.

Ryan’s budget also seeks to eliminate deficits by 2040. The Club for Growth has called for a budget that balances within the decade. Chocola said the budget contains “several important reforms and pro-growth policies” but is not enough.

“The Club for Growth urges Republicans to support a budget that balances in the near future and complies with the Budget Control Act,” he said.

The attack from the right comes as Ryan is facing a far more vigorous outcry from Democrats—who believe this plan slashes programs for the poor and elderly even while cutting taxes for the wealthy.

They have also complained that the Ryan plan slices agency budgets by $18 billion more than a year-long cap agreed to in the debt deal—a key concession made to conservatives whom Ryan will need to get his budget plan through the House.

With Democrats unified against Ryan’s plan, the Club for Growth statement could pose problems for its passage in the House if it persuades the GOP’s restive caucus to waver in its support.

Some centrist Republicans are also anxious about Ryan’s plan—fearful it will set the House on a path to another nasty clash with the Senate just weeks before the November election.