A Conservative spokesperson said that "Andrew Feldman always said that he would serve alongside the Prime Minister for as long as he was needed," according to Politics Home. 

“The Prime Minister has asked him to stay as chairman of the Conservative party whilst the leadership campaign takes place. He will ensure that the party conference is properly delivered in the autumn.

“Lord Feldman will step down when the Prime Minister leaves Downing Street.”

He became co-chairman of the party in 2010 before becoming the sole holder of the post after last year’s general election victory.

Source ; MENA