LONDON, July 11 (Xinhua) -- British Home Secretary Theresa May is set to be declared the new Conservative Party leader and the country's second female prime minister after her rival Andrea Leadsom quit the leadership race Monday.

Energy Minister Andrea Leadsom Monday withdrew from the Tory leadership race, backing the only remaining candidate Theresa May to be the next party leader and British prime minister.

Speaking in central London, Leadsom said she had the support of less than 25 percent of the parliamentary party.

That is not enough to run a strong, stable government, she said, adding that the interests of the country are best served by having a strong prime minister.

The energy minister also offered her "full support" to the only remaining candidate Theresa May, the Home Secretary and frontrunner in the Tory leadership contest.

Leadsom said May was "ideally placed" to implement British exit from the European Union (EU).

Chair of the Party's 1922 Committee Graham Brady confirmed Theresa May is now the only remaining candidate in the leadership race, and the committee will not reopen a leadership contest.