US President Barack Obama had a busy day yesterday as he appeared at not just one, but two A-list fundraising events in Manhattan – raising a total of $4.5 million.

However, Barack Obama’s re-election campaign will not have to pay the full cost of his jaunt to New York City, because he combined the trip with an official event which will be charged to the taxpayers.

Before the fundraisers, one at Sarah Jessica Parker’s house and one at the five-star Plaza Hotel, Barack Obama scheduled a visit to the World Trade Center site.

Following his visits across New York Barack Obama headed home to the White House in Washington DC aboard the presidential helicopter, Marine One.

Barack Obama has now held more fundraising events than the last six presidents combined, leading to his opponents coining the derisive nickname “Campaigner in Chief”.

He frequently combines the events with his official duties, which allows his re-election campaign to defray the President’s travel costs by charging part of them to the public purse.

For a trip like yesterday’s, involving both official duties and campaign events, a formula is applied so that the campaign pays part of the costs – but it still works out cheaper than making a trip purely for campaigning.

Barack Obama must be accompanied by Secret Service protection and fly on Air Force One at all times for security reasons, further increasing the cost of his travel.

The World Trade Center, which Barack Obama has visited several times before, is a major building project and recipient of generous federal aid, as well as an iconic national memorial.

It is unclear what prompted Barack Obama to return to the site – where he took the chance to hail “the American spirit” – on this occasion.

Before the fundraisers, one at Sarah Jessica Parker's house and one at the five-star Plaza Hotel, Barack Obama scheduled a visit to the World Trade Center site

The intimate dinner at the house of Sarah Jessica Parker and her actor husband Matthew Broderick banked about $2 million, with 50 people paying $40,000 each to attend.

Speaking in a dimly-lit, art-filled room, Barack Obama told supporters they would play a critical role in an election that would determine a vision for the nation’s future.

“You’re the tie-breaker,” he said.

“You’re the ultimate arbiter of which direction this country goes.”

Among the celebrities on hand to hear Barack Obama’s remarks were Oscar winner Meryl Streep, fashion designer Michael Kors and Vogue editor Anna Wintour, who moderated a private question-and-answer session between the President and the guests. Matthew Broderick, who was starring in a Broadway musical, was absent.

The night’s second glitzy fundraiser, which included a performance from Mariah Carey and a speech by singer Alicia Keys, yielded the Obama campaign at least $2.5 million.

Some New Yorkers reacted with anger at the prospect of footing the bill for Barack Obama’s fundraising visit to the city.

Much of downtown Manhattan was temporarily sealed off for the duration of Barack Obama’s visit, and the street in the West Village neighborhood where Sarah Jessica Parker’s house is situated was closed to pedestrians.

Some pedestrians bemoaned the disruption caused to the New York streets by the presidential motorcade – Mary Grach told ABC that Barack Obama’s visit was “really inconveniencing a lot of commuters”.

She added: “There has to be a better way to go about it rather than putting out how many thousands of riders out of commission, and having to find another way home.”

In 2004, Democrats criticized George W. Bush for combining fundraisers with official duties, and Republicans have responded in kind this year.

Barack Obama has been furiously fundraising ever since a Supreme Court decision removed most restrictions on spending by super PACs, outside groups which raise money to promote causes and candidates.

The President initially opposed super PACs, but earlier this year he relented and allowed top officials to speak at fundraising events organized by such groups.

The Republican party has officially complained about Barack Obama’s campaign activities.

In a letter, Reince Priebus, Republican National Committee chairman, alleged: “Throughout his administration, but particularly in recent weeks, President Obama has been passing off campaign travel as <<official events>>, thereby allowing taxpayers, rather than his campaign, to pay for his re-election efforts.”

During the 2008 election, Barack Obama declined public money for his campaign, allowing him to raise an unlimited amount privately.

He ended up spending around $730 million, almost double the amount raised by his rival John McCain.

Neither Barack Obama nor his Republican opponent Mitt Romney is expected to take public financing for November’s election.