Mitt Romney is catching up in the race for campaign cash.

Romney and the Republican National Committee, which is spending money on behalf of the Republican candidate, brought in $40.1 million during April, according to a campaign statement. That’s just shy of the $43.6 million raised by the Obama campaign and the Democratic National Committee during the same period.

The figures represent a turn of fortune for Romney in comparison with the previous month. When Romney became the presumptive nominee, he started raising money for the RNC at his fundraisers and collecting checks of $40,000 or more from one person. In March, he raised $12.7 million, compared with $35.1 million for the president’s campaign.

Romney has stepped up fundraising in recent weeks with events every day or two. On Thursday, he held a $50,000-a-plate lunch fundraiser at the Epping Forest Yacht Club in Jacksonville, Fla., decrying President Obama’s plans to let tax cuts on the wealthy expire. A day earlier, Romney said he raised $2 million during an event in Coral Gables, Fla.

The Romney campaign appears to have had a boost in small-dollar contributions, a crucial sign of support from donors of average means who will drive the volunteer efforts on his behalf. Until now, Romney has had weak fundraising from such small donors, lagging behind his rivals for the Republican nomination and far behind Obama’s campaign.

The Romney campaign reported $10.1 million coming in donations under $250, including funds for the RNC.

“We are pleased with the strong support we have received from Americans across the country who are looking for new leadership in the White House,” Spencer Zwick, the campaign’s national finance chairman, said in a statement.

Obama campaign manager Jim Messina said in an online video that 169,500 new donors gave to Obama in April, “putting us within reach of 2 million donors this election cycle. . . . That makes our campaign different, and it’s how we’re going to build a winning organization across the country.”

Campaign spending in the presidential race is heating up, especially on the airwaves. Obama’s campaign has begun its first significant television ad buys, announcing plans to spend $25 million during May. The campaign unveiled spots this week attacking Romney’s record as the head of Bain Capital.

The conservative group Crossroads GPS announced its own $25  million round of advertising over the next four weeks, attacking Obama over job creation, his signature health-care law and the national debt.

Obama’s push onto the airwaves is not enough to match what conservative interest groups are spending. Obama spent $3.6 million on broadcast television for the week ending Sunday, according to Kantar Media/CMAG.

Two conservative groups, Americans for Prosperity and the Romney-backing super PAC Restore Our Future, spent a combined $4 million that week. Romney’s campaign has not started running ads since he effectively secured the GOP nomination.

But Obama’s campaign appears to be far ahead in mobilizing voters on the ground, opening 42 field offices and hiring 120 staffers in April.