George HW Bush and his son George W Bush did not vote for fellow Republican Donald Trump in the presidential election last year, says the author of a new book on the former presidents.

The elder Bush voted for Hillary Clinton, while his son voted for neither Mr Trump nor his Democratic challenger, or “none of the above”, said Mark K Updegrove, who wrote The Last Republicans with the co-operation of the two Bushes. Harper Collins will publish the book on November 14th.

In an interview with the New York Times, Updegrove said the elder Bush (93) who served as president from 1989-1993, had an instinctive dislike of Mr Trump though he did not know him personally.

In an interview during the 2016 presidential campaign, he told the author that Mr Trump was a “blowhard”, driven by “a certain ego” and lacking a commitment to public service.

The younger Bush (71) who served in the White House from 2001-2009, believed Mr Trump lacked both humility and a necessary understanding of the presidency, Updegrove said in previewing the book about the relationship between the Bushes.

During the campaign, George W Bush told the author that he feared he would turn out to be the last Republican elected president.

“At the time, I think he was concerned that Hillary Clinton would win,” Updegrove told the Times.

“But if you look at his values and those shared by his father and Ronald Reagan, they are very much in contrast to the values of the Republican Party today, in particular the platform that Mr Trump ran on, which is essentially protectionism and a certain xenophobia,” said Updegrove, a historian who has written several books about the presidency.

Updegrove could not be reached for further comment.

“The American people voted to elect an outsider who is capable of implementing real, positive, and needed change – instead of a lifelong politician beholden to special interests,” White House spokeswoman Sarah Sanders said in a statement.

“If they were interested in continuing decades of costly mistakes, another establishment politician more concerned with putting politics over people would have won.” – Reuters