CONCORD — House Republicans on Thursday approved a proposed constitutional amendment that would bar a state income tax.

The 15-5 vote on the Ways and Means Committee sends the amendment, CACR 13, to the full House for a vote in January. Republicans and Democrats on the committee split straight along party lines.

The brief proposal is worded: “No new tax shall be levied, directly or indirectly, upon a person's income, from whatever source it is derived.”

A constitutional amendment has to pass by a three-fifths majority in both the House and Senate, before it can go on the general election ballot in 2012. It takes a two-thirds majority of the voters to pass a constitutional amendment.

Rep. Keith Murphy, R-Bedford, said during discussion that the bill is straightforward.

“It is clear, concise and simple and the intent is very simply that there be no new taxes on individual income in New Hampshire forever.”

Rep. Susan Almy, D-Lebanon, led Democrats in fighting the amendment. She said the bill, “is nothing like simple, or clear, I'm afraid.”

Almy argued that by barring even indirect taxes on income, the amendment would block new taxes of all kinds, because all taxes are paid from income.

“I can see us fighting over the meaning of the Constitution on every tax change,” she said.

Speaker of the House William O'Brien praised the committee action, and predicted the measure will pass the House in January.

He said the bill is “a great protection against future generation big spenders and ensures the state's tradition of frugality and local control ... We must remain good stewards of taxpayers' money. Good government is one that serves the people and is limited and fiscally prudent.”

House Majority Leader D.J. Bettencourt, R-Salem, said: “This measure comes at an incredibly important time and certainly should be approved by the full House and Senate in time to get it on the 2012 ballot.”

Rep. Frank Sapareto, R-Derry, said he thinks the amendment is a good idea. He disagreed with Almy's argument that taxes of all kinds will be barred by the measure.

“A tax on sales would not be a tax on income. There is a clear definition here,” he said.

Rep. Christine Hamm, D-Hopkinton, said that Republicans repeatedly defeated similar amendments when they controlled the Legislature before 2006.

“The policy has always been not to tie the hands of future Legislatures,” Hamm said.

Almy noted that the state may be slowly left behind as the economy changes over the next century, unable to shift tax policy because of the impediment the amendment creates.

“This will freeze revenues,” she said, “and it could cause people and business to leave the state because they can't live with the tax regimen.”