The Defence Secretary made the comments during a visit to the University of London Royal Holloway on Friday.
Although he had visited the university to speak to students about British security and defence he was met by a group chanting, “gay, straight, black or white, marriage is a civil right.”
The group were protesting following a letter Mr Hammond sent to a student stating he wouldn’t be supporting the government’s proposed same-sex marriage bill.
Mr Hammond met with students Joe Raymont and Jack Saafery-Rowe and said he was ‘concerned’ with the government’s plans and that he believed gay couples would take religious organisations to court if they refused to hold same-sex ceremonies.
When pressed on the subject he stated that current civil partnership legislation removed discrimination towards same-sex couples and that any further changes would be the same as legalising incest, where it is illegal for siblings to marry.
MP’s are due to vote on the second reading of the same-sex marriage bill on 5th February.