Mitt Romney is being accused of deliberately trying to make it harder for same-sex couples to register the birth details of their children during his time as governor of Massachusetts.

According to the Boston Globe, then-Governor Mitt Romney rejected a request from the state’s Registry of Vital Records and Statistics to revise birth certificate forms so they could cater for same-sex parents, following the state’s decision to legalise equal marriage in 2003.

The Republican presidential candidate, who remains opposed to equal marriage, is said to have fought against plans to amend Massachusetts’ birth certificates so the box for “father” would be relabeled “father or second parent,’’ reflecting the change in the law.

However, the Globe reports that Mr Romney instead insisted that his top legal staff individually review the circumstances of every child born to same-sex parents in the state.

Only after winning approval from the governor’s lawyers could hospital officials be permitted to cross out by hand the word “father’’ on individual birth certificates, and then write in “second parent,’’ in ink.

Such was Mr Romney’s determination to scrutinise the personal arrangements of gay parents in the state that a significant number of emails and memos were sent from his office to the Department of Public Health, which oversees the Registry of Vital Records.

Despite warnings from the department that the actions were putting same-sex parents at a disadvantage, and was legally questionable, the practice continued until Mr Romney left office in January 2007.