More than a month after announcing that she was exploring a Senate bid, Rep. Corrine Brown (D-Fla.) has raised less than $5,000 for that effort and has yet to file any paperwork to form an exploratory committee with the Federal Election Commission.

Brown surprised many of her Democratic colleagues by announcing on May 30 that she was considering challenging fellow Rep. Kendrick Meek (D) in the Senate primary.

She also doesn’t appear to be ramping up fundraising for her House campaign — which could be transferred into a future Senate campaign account — in the wake of her announcement.

According to Chief of Staff Ronnie Simmons, Brown raised just a little more than $44,000 in the second quarter. That’s about a third of the more than $125,000 Brown raised in the first three months of the year for her re-election campaign.

Simmons said Tuesday that Brown’s depressed House fundraising numbers can be attributed to the fact that the Congresswoman spent the month of June laying the groundwork for her Senate bid.

“She wanted to make sure she went out and talked to her supporters and contributors beforehand, before hitting them up for the money,— Simmons said.

“We were pretty sure we could have raised $300,000 or $400,000 but … we’re fully aware of [Meek’s] and [Republican Gov. Charlie] Crist’s fundraising activities, and she just chose not to file until after July 1,— he added.

Simmons said Brown’s efforts during the month of June are already paying off, noting that the Congresswoman had earned some $300,000 in pledges from supporters. He added that Brown had asked those supporters to hold off writing or delivering their checks until the third quarter began so that her September fundraising report could show the strength of her campaign.

“You will see her wheels spinning from here forward, trust me,— Simmons said. “A couple million is the goal— for the primary.

She’ll certainly need all the money she can get as Meek, who entered the race in January, has already passed the $3 million mark, according to an announcement from his campaign Tuesday.

Meek raised $1.2 million during the second quarter, bringing his fundraising total this cycle to just less than $3.1 million.

Meek’s campaign did not have cash-on-hand or second-quarter expenditure figures available as of Tuesday morning. His cycle-to-date fundraising total includes a $300,000 transfer from his House account during the first quarter.

Since entering the race, Meek has been crisscrossing the state and has now set up field offices in four cities as he works to lock down the Democratic nomination. The South Florida Congressman spent the Fourth of July recess campaigning and raising money in North Florida.

North Miami Mayor Kevin Burns (D) is also in the primary.

In a letter thanking supporters Tuesday morning, Meek said his campaign is working hard early to be in the best position to win in 2010.

“Over 4,000 individuals made a financial contribution to this movement, demonstrating that our support is both wide and deep,— Meek wrote. “No other non-incumbent Democratic candidate for the U.S. Senate today is raising the funds necessary to grow the movement that we are building together.—

On the Republican side, former Florida Speaker Marco Rubio announced in an e-mail Tuesday that his campaign raised $340,000 during the second quarter for his Senate bid.

Rubio is a darling of many social and fiscal conservatives, but his second-quarter fundraising total only serves to underscore the fact that he is the underdog in the Republican primary against Crist, who has the backing of the National Republican Senatorial Committee, the GOP’s establishment in Washington and retiring Sen. Mel Martinez (R), the man he’s vying to succeed.

Crist raised $3 million in just six weeks since announcing his candidacy, according to a report last week in the Orlando Sentinel.

Meanwhile, there was mixed news Tuesday for Republicans in a few of the other closely watched Senate campaigns.

In New Hampshire, Attorney General Kelly Ayotte (R) announced Tuesday that she is resigning, effective July 17, to explore a bid for retiring Sen. Judd Gregg’s (R) seat in 2010.

Her move is a major recruiting victory for Senate Republicans, who had been actively trying to get her in the race.

Although Ayotte was appointed to her post and has never been elected statewide, recent public polling showed she would be competitive in a race against Rep. Paul Hodes, the likely Democratic nominee.

But the news out of Kentucky yesterday was not as positive for Republicans. Sen. Jim Bunning (R) acknowledged in a conference call with state reporters that Kentucky Secretary of State Trey Grayson’s (R) $600,000 haul in the second quarter would outpace his own fundraising total.

Grayson announced a Senate exploratory committee in late April and said at the time that he had “no plans to run against Sen. Bunning in 2010,— indicating instead that he would only run if Bunning decided to retire.

While more recent comments by Grayson seem to indicate a possible change in that stance, Bunning made it clear again Tuesday that he intends to run in 2010 and said he remains confident Grayson won’t run against him.

That comment came as unwelcome news to some high-level party insiders who were hoping Bunning would reassess the race after the end of the second quarter.

In February, Bunning set a $2 million fundraising goal for himself by the end of June, and then in May, Bunning said he would “take another look at the race— if he didn’t meet his own internal fundraising goals.