DES MOINES -- A plan to establish a statewide core curriculum for K-12 schools hit a roadblock Monday, after the Iowa House approved a change to the proposal that could endanger its final passage.

If it becomes law, the plan would require high school grades to implement the state's specified course requirements by 2012, and for kindergarten through eighth grades by 2014.

A bipartisan amendment narrowly accepted by the House calls for the establishment of more rigorous content standards than originally proposed by the bill and makes recommendations for considering future performance standards.

"We're trying to go two steps beyond what the bill (would do)," said Rep. Phil Wise, D-Keokuk, one of the change's sponsors.

After the House approved the amended bill, 97-3, House Majority Leader Kevin McCarthy, D-Des Moines, used a procedural maneuver to delay it from being shipped back to the Senate for final approval.

McCarthy said neither that chamber nor Gov. Chet Culver would approve the changes, so he hoped to resolve those issues first before releasing it.

The change would cost the state more than $100 million in assessments and would jeopardize Iowa's federal No Child Left Behind funding, said Culver spokesman Brad Anderson.

BUDGET UNDER WRAPS -- Lawmakers hope to conclude the session within the next week, even though large parts of the proposed budget have not yet been introduced.

Sen. Steve Kettering, R-Lake View, said Monday that Iowans deserve a chance to review the budget as a whole before it comes up for debate.

"Half of the budget remains to be disclosed, he said.

Rep. Jo Oldson, D-Des Moines, said the budget will have few surprises, with almost no growth in most state agencies.

"You'll see a very fiscally responsible, balanced budget," she said.

The legislators made their comments on the Iowa Public Radio program "The Exchange."

At least two major budget bills have not yet been introduced. The first, dealing with infrastructure spending, normally is available at this point of the session. The second is a catch-all measure that is often among the final bills to pass.

Legislative Democrats have issued no estimates about the size of the overall budget. It likely will be in the neighborhood of $6.4 billion, the total requested by Gov. Chet Culver.

THE BOXES EMERGE -- In a sure sign the Legislature is close to adjourning, the high school pages who assist lawmakers began assembling packing boxes Monday.

Corners of the House and Senate started filling with boxes as retiring lawmakers gave farewell speeches.

The scheduled end of the Legislature's session is set for April 22, although lawmakers could end up adjourning before or after that date.