— -- Republican presidential candidate Ted Cruz raised nearly $20 million over the last three months, giving the Texas senator an impressive haul as he heads into the new year and the first nominating contests of the presidential race.
Campaign manager Jeff Roe revealed the fundraising numbers to campaign staffers in a memo first reported by the Wall Street Journal.
"We will conclude 2015 with having raised over $45 million," wrote Roe in the memo.
That means the campaign raised nearly $20 million dollars in the fourth quarter of the year, up from the $12.2 million raised in the third quarter.
According to Roe's memo, the campaign had over 670,000 donations from over 300,000 donors in 2015. Some of those donors are what the campaign calls "sustainers" who are giving recurring payments on a monthly basis. Roe wrote that those recurring donations can fund the entire campaign's field operation.
"Some campaigns are focused solely on a man, some on a movement. Ours is a hybrid of the two built to win. We have brought together, and continue to build, a grassroots army of courageous conservatives committed to electing Ted Cruz to reignite the promise of America. Just over a month away from the start of the caucuses and primaries we have a network in place with the resources required to win that is the envy of every other campaign," Roe writes in the memo.
The surge in fundraising comes as Cruz rises in the polls. A recent CNN/ORC poll showed Cruz in second place to Donald Trump. He is currently leading in Iowa, the first state to hold its caucuses.
Cruz's fundraising prowess is something he touts on the campaign trail, often noting his campaign has more cash on hand than Jeb Bush.
"We finished the last fundraising quarter with more money in the bank than any Republican in the field. That's part of why the Washington establishment is panicking because they are used to having conservatives with no money, no ability to communicate where they can just swap them with false attack ads," said Cruz at a press conference in Las Vegas, Nev. Dec. 17.
Last quarter, Ben Carson and Jeb Bush raised more money than Cruz, but Cruz had a lower burn rate. His campaign had over $13 million on hand, more cash on hand than any of the GOP field. Cruz's campaign has not revealed how much cash they have on hand as the fourth quarter wraps and they enter 2016.
Carson’s campaign manager told ABC News that they expect to raise $23 million this quarter, but are still waiting for final numbers.
ABC News' Katherine Faulders contributed to this report.