The sex crimes prosecutor who questioned a woman accusing Brett Kavanaugh of sexual assault has explained why she would not bring criminal charges against the Supreme Court nominee.

Rachel Mitchell wrote in a new memo sent to Senate Republicans that she does not believe a “reasonable prosecutor would bring this case based on the evidence before the Committee”.

Ms Mitchell is a sex crimes prosecutor Republicans hired to question Christine Blasey Ford about her claims against Mr Kavanaugh during a Senate Judiciary Committee hearing last week.

Supreme Court Kavanaugh
Christine Blasey Ford shakes hands with Phoenix prosecutor Rachel Mitchell (Andrew Harnik/AP)

Ms Mitchell argued that there are inconsistencies in Ms Ford’s narrative and says no one has corroborated her account.

The hearing, which featured evidence from Ms Ford and Mr Kavanaugh, was not a criminal proceeding, but part of the confirmation process for Mr Kavanaugh.

Mr Kavanaugh has denied the allegations.

He has been nominated by President Donald Trump for the Supreme Court, the body which rules on key issues such as abortion and same-sex marriage, as a potential replacement for the retiring Anthony Kennedy.

Supreme Court nomination processes have recently been fiercely contested on partisan lines.

Mr Trump successfully nominated Neil Gorsuch for the vacancy created by the death in 2016 of Antonin Scalia after former president Barack Obama failed to win backing for his choice, Merrick Garland, in a process which ended shortly before Mr Trump took over the reins.