Jacob Rees-Mogg has announced he will back Boris Johnson in any upcoming Conservative leadership bid.
The European Research Group chairman described the former foreign secretary as being a charismatic leader “in a different league” from other leadership hopefuls and someone who creates "excitement" around politics.
“I am not going to stand but I will be supporting Boris Johnson," he told talkRADIO's Julia Hartley-Brewer.
Last Thursday, Mr Johnson told a business conference in Manchester he would run for Tory leader, saying: "I'm going to go for it. Of course I'm going to go for it."
However, it is suggested that One Nation Conservative Caucus – a new group of Conservative MPs including Amber Rudd – could attempt to block a leadership bid by Mr Johnson.
Mr Rees-Mogg dismissed the group and said their focus on stopping candidates like Mr Johnson shows the former foreign secretaries popularity.
Former work and pensions secretary Esther McVey MP and secretary of international development Rory Stewart MP have put themselves forward for the role.
Mr Rees-Mogg said: “They are highly competent and would make excellent Prime Ministers in ordinary circumstances, but we are not in ordinary circumstances.
“We are facing a constitutional crisis and a Tory Party that is looking as if it could be in a decline that it can’t get out of, and that needs somebody truly exceptional to do it which is why I will be supporting Boris.”
Prime Minister Theresa May is yet to set a date for her departure but she has agreed to discussions in early June on the election of her successor.