Lady GaGa turned down $1 million to appear at the US Republican conference last year.

The 'Bad Romance' singer was offered the huge sum to appear at the event in August 2012, and the party even promised £150,000 of the money would go to domestic violence shelter if she agreed to perform.

Other artists to say no to the event included country star Dolly Parton and rapper Pitbull, although they were offered lower fees.

The discoveries were made in a lawsuit filed by the Republican party's fundraising organisation, American Action Network against Cater America LLC, who organised entertainment for the event.

Gaga, 27, has previously been critical of Republican presidential candidate Mitt Romney, and showed support for current US president Barack Obama, when he was elected ahead of his opponent for the Democrat party in November last year.

Upon hearing the news of his re-election, she tweeted: ''I JUST GOT OFF STAGE IN COLUMBIA!! CONGRATULATIONS MR. PRESIDENT ‪@BarackObama We are so proud to be American tonight! YES!!! YES! YES!! (sic).''

Acts who went on to perform at the Republican National Convention included Kid Rock, Journey and Lynyrd Skynyrd.

Gaga is currently in a wheelchair while she recovers from hip surgery to repair a labral tear on her right hip, which had caused her to cancel a number of shows on the US leg of her Born This Way Ball tour.

Once she is properly recovered Gaga is expected to put the finishing touches to her third album 'ARTPOP', which is expected to be released later this year.