Gov. Mark Dayton is outpacing his GOP rivals and now has nearly twice as much cash on hand as all four Republican gubernatorial candidates put together, according to campaign-finance reports released Tuesday.

The pre-election reports also show that the DFL Party and its legislative committees are eclipsing Republican counterparts in the money battle, having raised three times as much.

But when it comes to outside interest groups, those that lean Republican are holding their own against Democratic groups, and both will be training much of their firepower on what promises to be a furious and high-dollar battle for control of the Minnesota House this fall.

While it's still early for outside groups to unleash their full might, the top 10 independent spending committees have amassed more than $3 million for the months ahead. Alliance for a Better Minnesota and its funding arms, a key factor for Dayton and Democrats, has banked $1.4 million in cash.

Meanwhile, business groups and the conservative Freedom Club have stashed away $1.2 million to help Republicans statewide, but with a particular focus on the Legislature, which now is controlled by Democrats.

"I think you are going to see the bulk of business money focused on the House," said Charlie Weaver, executive director of the Minnesota Business Partnership. He is involved in several spending groups that work to elect what he calls "pro-business candidates."

DFL Party Chair Ken Martin said that robust party fundraising will help Democrats across the board.

"We are in an extremely strong position to help our candidates win elections up and down the ballot this fall," he said.

According to the pre-election reports, the state DFL and its legislative committees have raised almost $2.4 million. By comparison, the Republican Party and its legislative affiliates have raised $885,000.

The two party powers are a bit more evenly matched when it comes to spending. The DFL groups have spent $1.7 million, and the Republican groups have spent $1.2 million. The Republican Party also still has debt from earlier lean times, owing vendors $538,000.

Money chase ramps up

With the legislative session over and the state conventions done, the money chase now begins in earnest.

Since last year, Dayton has brought in more than $1.4 million for his re-election campaign and has more than $750,000 cash on hand. Still, Dayton has raised only $160,000 in the past two months — a lackluster showing that his campaign blames on the legislative session.

Dayton has agreed to abide by spending limits to get a public subsidy for the 2014 contest. That could net him an extra $448,000 from the state after the August primary.

His Republican rivals are locked in a four-way primary contest that will keep their names in the news, but could also drain their bank accounts.

So far, Wayzata businessman Scott Honour, former House Speaker Kurt Zellers, former House Minority Leader Marty Seifert and Hennepin County Commissioner Jeff Johnson have been raising money slowly and spending it quickly. But together the four have raised and spent more than twice what the governor has brought in this year, according to reports that include funding from the first of the year through the end of May.

For Johnson, who won endorsement at last month's Republican state convention, the weeks ahead will be filled with fundraising. He said he will need $1 million to beat out his three fellow Republicans in a primary. At the end of May, Johnson had $33,000 in the bank.

Most of his spending went to win the endorsement. Half of the $263,000 Johnson has spent up to now came in the two months leading up to the convention. That included everything from $1,200 on convention pizza to $800 for helium-filled balloons. The campaign also ponied up $3,800 for T-shirts and $2,700 on custom "Johnson for Governor" hotel-room "key cards" for Republican delegates.

But the Johnson campaign said the investment in attaining endorsement is paying off. "We have raised over $90,000 in just two weeks, and the rate of fundraising increases daily," campaign manager Scot Crockett said.

Zellers has raised more than Johnson — $543,000 since getting in the race last year — but spent it nearly as quickly. His largest expenses include lists, mailings and databases.

Seifert, who jumped in the race late last year, has brought in about $250,000 in donations and recently lent his campaign $19,500.

Honour, a first-time candidate, has brought in more than any other Republican — about $1.2 million since last spring — through a combination of fundraising and $401,000 in personal loans he has made to his campaign.

This year, his fundraising from others has dropped off and his personal investment has ticked up, according to public data. But the Honour campaign says it is working to turn that around.

"In the two weeks since I've joined Scott, I've seen tremendous enthusiasm from grass-roots activists and donors," said Sen. Karin Housley, R-St. Marys Point, who is Honour's running mate.

Honour, who is independently wealthy, is the only candidate in the field who has not agreed to abide by the $4 million spending limit that earns candidates a public subsidy.

If Honour wins the primary, Dayton and the Independence Party gubernatorial candidate will each get to split the $300,000 that otherwise would have gone to Honour.

Dayton's campaign has spent its cash largely on staff and consultants. It also spent a little more than $5,000 on health-insurance premiums paid to MNsure, the controversial health-exchange program that grew out of the federal Affordable Care Act.

"It's saving the campaign money," said Katharine Tinucci, Dayton's campaign manager.

Rachel E. Stassen-Berger • Twitter: @rachelsb

Glenn Howatt • Twitter: @glennhowatt