Scottish Secretary David Mundell said "nobody could have worked harder" as Theresa May announced her resignation.
The Prime Minister declared she will step down as Conservative leader on June 7 after failing to deliver her Brexit deal.
In a speech outside Downing Street, she talked about her plan to resign after facing increasing calls from within her own party and the opposition benches to do so.
In a statement released shortly after he resignation, Scottish Secretary David Mundell said:
As she concluded her speech, which was broadcasted live, the Conservative leader appeared to become tearful.
Tory MP's are expected to announce their leadership bids within the next few days.