After months of lower-than-hoped-for revenue collections, Missouri's state government saw an unexpected boost in income in December. And that could result in lower tensions over money in the Capitol.

State income – primarily taxes – rose 10.7 percent in December, compared to the same period a year ago. The chief reason: higher collections in individual income taxes and sales taxes.

As a result, overall revenue for the first half of the fiscal year is now up 5.1 percent, just a shade below the 5.2 percent that Gov. Jay Nixon’s administration had projected. The December deluge ends a dip in state revenue collections that threatened current state spending for the fiscal year that ends June 30.

The fiscal improvement could put Nixon and his budget team in a better position when the General Assembly goes back into session on Wednesday. Budget issues will be legislators’ chief concern for the next few months, as they craft a new budget for the coming fiscal year that begins July 1.

Legislators and Nixon’s staff have agreed on a projected increase of 3.6 percent in state income for the new fiscal year (FY2016). But they continue to split sharply over expected income during the current fiscal year. The governor’s budget team has said that the budget approved by the General Assembly was way out of balance because of last-minute tax breaks; Nixon subsequently withheld or vetoed about $1.2 billion.

December’s income collections were larger than expected, said state Budget Director Linda Luebbering. As a result, Nixon will likely drop threats – for now – to withhold even more appropriations in the current budget. What's unclear is what effect the improved fiscal picture will have on legislators.

Amendment 10’s approval in November adds another element to the state’s budget battles. The General Assembly can now overturn the governor’s budget vetoes or withholds. Some legislators are asserting that power is retroactive to the current budget, while others say that Amendment 10 applies only to future budgets.

December's strong showing actually fits in with current trends. A year ago, December 2013 had shown an even larger financial surge -- about 25 percent over December 2012 -- that also was due largely to higher collections from individual income taxes and sales taxes.

So far this fiscal year, the 5.1 percent increase translates to an additional $190 million in general revenue, compared to the same period in 2013. About $82 million of that increase came during December.

Here's the December revenue breakdown, as released by the state Office of Administration:

GROSS COLLECTIONS BY TAX TYPE

Individual income tax collections

Increased 6.3 percent for the year, from $2.71 billion last year to $2.88 billion this year.

Increased 9.6 percent for the month.

Sales and use tax collections

Increased 3.0 percent for the year, from $979.6 million last year to $1.01 billion this year.

Increased 4.8 percent for the month.

Corporate income and corporate franchise tax collections

Increased 3.3 percent for the year, from $260.6 million last year to $269.3 million this year.

Increased 19.8 percent for the month.

All other collections

Decreased 5.8 percent for the year, from $187.1 million last year to $176.4 million this year.

Decreased 19.8 percent for the month.

Refunds