"I did it for fun, not to offend," Yeo said.
An acclaimed portrait artist in England, Yeo's work has been displayed in London's National Portrait Gallery.
A spokesman for the Republican Party in Texas called the portrait "distasteful," asking, "Why would anyone want to make a picture of our president from pornographic material?"
A spokesman for Republicans Abroad International described the portrait as a "cheap stunt" in an interview with The Sun.
Yeo has no apparent political bias, and has recently completed portraits of publisher Rupert Murdoch and former Prime Minister Tony Blair.
The artwork, titled "Bush 2007," is part of an exhibition at Lazarides Gallery in London's Soho district. The image will available in a limited edition run of 150 prints, measuring 33 by 22 inches, in a few weeks.