The brother of the male Google engineer fired after a memo saying women are biologically less likely to get to the top of the tech world has hit back, telling critics: 'Read the whole thing.'

James Damore, 28, was terminated by the internet giant on Monday for a violation of the company's code of conduct after the memo became a viral phenomenon.

It also said Google was censoring conservative members of staff, and Damore is now considering his legal options, with some lawyers saying he has a case under the First Amendment for suing Google. He has already filed a labor complaint over his treatment.

On Tuesday his younger brother Josh, 23, defended James and said that his critics have been selectively quoting from the text.

He said: 'It's a 10-page work so you can pull a lot of words out of that and manipulate what he wrote. It's important to read the whole thing. Damore was brought up with Joshua and their older brother John Damore Jr, 30, in Romeville, Illinois, by parents John and Deborah. 

He studied at Illinois Mathematics and Science Academy, graduated with a degree in molecular and cellular biology from the University of Illinois at Urbana-Champaign, then was a postgraduate student at MIT.

His mother is a computer science graduate who is now an executive at a logistics company.

He is now at the center of one of the biggest storms to hit Google, whose parents company Alphabet is worth $649 billion. 

Damore had posted on Facebook when he joined Google in 2013 about his excitement - but four years later his career was terminated with a scathing email from the company's most senior staff to all employees.

On Monday Google CEO Sundar Pichai said: 'portions of the memo violate our code of conduct and cross the line by advancing harmful gender stereotypes in our workplace.' 

Pichai said he was cutting his family vacation short in order to return to Google headquarters and deal with the aftermath of Damore's essay on gender.

In a note emailed to Google employees on Monday, Pichai said employees have a right to express themselves but 'to suggest a group of our colleagues have traits that make them less biologically suited to that work is offensive and not OK.'

Damore, who had worked at the tech company since 2013, confirmed to both Reuters and Bloomberg via emails that he had been fired.

Damore later told Reuters he was exploring all possible legal remedies and that before being fired he had submitted a charge to the US National Labor Relations Board accusing Google upper management of trying to shame him into silence.

'It's illegal to retaliate against an NLRB charge,' he wrote in the email.