Mitt Romney raised nearly $12.6 million for his primary battle in March, his campaign announced on Friday, in a sign of the Republican front-runner's growing strength toward winning the party's presidential nomination.
In addition, Romney has nearly $10.1 million cash in hand as he seeks to wrap up the nomination and focus on raising money for a difficult fight to unseat Democratic President Barack Obama in the November 6 election.
The $12.6 million figure, the best fund-raising month of his campaign, came at a time when Romney was still facing stiff competition from his last big conservative challenger, Rick Santorum, who has since dropped out of the race.
The amount was a sign of Romney's increasing momentum toward the nomination. In the last 12 months, his campaign raised $87 million in primary funds.
"Mitt Romney's continued strong fundraising shows that voters across the country are tired of the failures from President Obama. We will continue the hard work to raise the necessary funds to defeat President Obama and change the direction of the country," said Romney finance chairman Spencer Szwick.
Romney has also begun raising money for the general election jointly with the Republican National Committee. Romney's figures from that effort have not yet been disclosed.
A joint fund greatly increases how much a donor can give to help a candidate, thanks to larger contributions allowed for party organizations in addition to the campaign.
Campaigns can take only $2,500 during the primary process and another $2,500 for the general election. With a joint effort, a donor can also give up to $70,800 to the RNC and its local, state and district branches, according to the Federal Election Commission's guidelines for this election.
Both Republicans and Democrats are waging a war on who can raise the most money. Obama and his Democratic allies raised $53 million in March for the general election campaign, but donations to Democratic outside groups have lagged that of Republicans, a source of concern for Democrats.
The Romney campaign said that of the $87 million raised throughout the primary season thus far, $11.6 million came from relatively small donations of under $250. Some 286,520 donations under $250 had been received through the end of March.
Contributions came in from donors in all 50 states plus Washington D.C., and 89 percent of all donors can still donate again.
(Additional reporting by Alina Selyukh)