Theresa May is set to become Prime Minister after her rival Andrea Leadsom for Conservative Party leadership quit the race.

Leadsom, a Brexit campaigner and devout Christian, backed May and said she was "ideally placed" to implement Britain's exit from the European Union. The withdrawal leaves the door open for Theresa May to move into Number 10 Downing Street within days.

"Strong leadership is needed urgently" Leadsom said and a "nine week leadership campaign at such a critical moment for our country is undesirable".

She added: "A strong, unified government is needed."

Graham Brady, the chairman of the Tory's 1922 committee which makes decisions for the Party, confirmed the contest would not be reopened, meaning May could be confirmed as PM within hours.

Leadsom emerged from her campaign headquarters on Monday afternoon after a torrid weekend where she said she was best placed to be Prime Minister because she was a mother. She told the Times had "a very real stake" in the UK's future because she had children whereas May "possibly has nieces, nephews". Intense criticism erupted after the interview which led to Leadsom claiming she was "under attack".

But in a statement to announce her resignation she made no reference to the row which some of her supporters described as a "smear campaign".

David Burrowes, MP for Enfield and Southgate and a Christian, told Christian Today he was "personally disappointed" and said Leadsom had "acted in the best interests of the country".

He said he next Prime Minister "will be Theresa May" and said he was "relieved" the party could move forward.

"I am proud that we will have the second Conservative women PM and pleased that Theresa May is totally committed to Brexit and social justice".

But other Leadsom supporters were not so quick to praise May.

Iain Duncan Smith, the former work and pensions secretary and a Catholic told Sky News he was "somewhat appalled" by the attacks on Leadsom which he described as a "genuine operation" by her opponents.

He said this was a decision "for the best of this country" and the campaign had "become too divisive". But he declined to support Theresa May and said he was "through with backing people".

Adrian Hilton, a conservative Christian blogger and Leadsom backer, said he was "immensely saddened that the brave Brexiteer Andrea Leadsom" had pulled out of the race.

"It is telling that so much of the abuse aimed at her has been warped, anti-Christian and intensely personal – often coming from a faction within her own party who are intent on secularising our political culture and eradicating all vestiges of social conservatism in the name of 'modernisation'.

"When the predominantly pro-EU media and Establishment are ranged against you, it becomes impossible to move the narrative beyond personal attacks to important matters of policy.

"I can understand why she decided to quit, but with Remainers Theresa May and George Osborne now set to lead the UK out of the EU, I have no idea why David Cameron resigned."

A decision on when May will be appointed is expected to be announced later on Monday.