Sir Mike was previously unable to publicly back any candidate due to his position as a Vice Chair of the Conservative Party.
He has since stepped down from that position in order to back Penny’s campaign.
Sir Mike said that he has every confidence that she can secure the support of the Conservative Party and is the right person to lead the country.
He said: “I am very pleased to back Penny for Prime Minister. She has consistently proved herself to be a strong a decisive leader.”
Sir Mike added: “She was the first ever female Secretary of State for Defence and serves as a Royal Naval Reservist.”