Romney beats Obama by $35m in June fundraising
Mitt Romney's presidential campaign increased its fundraising lead over President Barack Obama in June, official figures show.
Both camps raised more than in May, when the Romney bid took in $77m and the Obama camp $60m.
The totals exclude millions raised by independent groups that support each candidate.
The Obama campaign released its June numbers in an email to donors.
"If we lose this election, it will be because we didn't close the gap enough when we had the chance," the email says, issuing another call for donations.
Mr Obama's campaign has been regularly warning supporters that he is in danger of becoming the first sitting president in history to be outspent by his opponent.
Super PAC rise
Mr Romney and the Republican National Committee have an estimated $160m cash in the bank to spend on the campaign, they confirmed on Monday.
About 20% - or $22.8m - of money raised by the two groups in June were from donations of $250 or less. The campaign said it received donations from all 50 states and from Washington DC.
Their rivals, the Obama campaign and the Democratic National Committee, had previously reported a combined $140m cash on hand at the end of May.
Campaign finance rules limit individuals to donations of $2,500 per donor per election cycle. National party committees are limited to $30,800 per donor per calendar year, but transfers can occur between the two.
However, independent groups known as political action committees (PACs) are allowed to fundraise without limits in order to support a candidate - but they cannot co-ordinate with the official campaign.
These groups are playing an increasingly prominent role in elections. Major "super PACs" supporting Mr Romney, including Restore our Future and American Crossroads, have raised a combined $91m.
According to Politico , backers of the main pro-Republican super PACs are aiming to raise as much as $1bn during this election cycle.
By contrast, Priorities USA Action, the main Democratic super PAC supporting Mr Obama, has raised just $40m so far, the New York Times reported on Sunday.
Campaign on the economy
Despite its fundraising bonanza, correspondents say the Romney campaign has struggled recently to gain the initiative.
Last week he found himself pressured on his response to the Supreme Court healthcare ruling, and he has faced renewed scrutiny over his financial affairs in recent days.
Several polls show the president retains a lead in some key swing states.
However, Mr Obama's re-election campaign found little to crow about in last Friday's lacklustre jobs report - a reminder of the US economy's precarious position, just four months before November's election.
On Monday, Mr Obama renewed calls to extend tax cuts for those making under $250,000 - but not for those earning above that sum.
The move is not expected to pass Congress but rather help Mr Obama frame his "economic fairness" argument in his campaign for re-election.