A fundraiser and birthday celebration for Mitt Romney's wife, Ann, being held Tuesday at the home of Donald and Melania Trump, has raised $600,000 for the Romney Campaign, a Trump spokesman told CBS News.

Tickets for the fundraiser cost $1,000 per person. The original invitation said the event would take place at 12:30 p.m. on Tuesday, but CBS News reported that due to overwhelming demand, it will now be divided into two shifts: one from noon to 1:15 p.m. and another from 1:30 to 3 p.m.

Tuesday's event at Trump's primary residence, a triplex on 5th Avenue, was originally only supposed to hold 200 people. But when capacity was filled within 48 hours of invitations going out, the campaign "began to panic," says [Trump spokesman Michael] Cohen. He says they asked to extend the number of people attending, which will now be 400.

Donald Trump endorsed Romney in February in Las Vegas and has since recorded robo-calls for the GOP presidential candidate. His spokesman told CBS News that the campaign asked Trump to hold another fundraiser later in the year after Romney officially secures the nomination.

The party comes a day after Ann Romney's birthday -- and almost a week after a dust-up over Democratic strategist Hilary Rosen's comment that the candidate's wife hadn't "worked a day in her life." Rosen later clarified that while she believed being a stay-at-home mom was hard work, her point was that Romney hadn't had to simultaneously raise her children and earn a paycheck. Ann Romney said on Sunday that the comments were like an "early birthday present," explaining to ABC News on Monday that she thought they helped bring motherhood into the national conversation.

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