Boris Johnson has said his annual salary of NZ$262,255 is not enough to live on.
The Sunday Times reports the UK Foreign Secretary told friends his annual earnings aren't enough because of his "extensive family responsibilities".
He has five children - four with his second wife and a fifth he had during an affair, which he tried to keep secret.
A YouGov poll published this week found Mr Johnson is now favourite to be the party's next leader among Conservative party members.
It's thought despite the rifts within the Tories his popularity is due to his pressure put on Theresa May's Brexit position.
In an interview with The Sun, Mr Johnson critiqued Prime Minister Theresa May and drew lines on Brexit negotiations.
Mr Johnson wants a two-year limit on any transition period, during which the UK should refuse to accept jurisdiction rulings from the European Union.
The interview revealed further differences between Mr Johnson and Ms May, who has said the length and terms of the transition period could be flexible.
But in an interview with the BBC, Ms May said she thought Mr Johnson was "behind her".
"What I have is a cabinet that is united in the mission of this government", she said.
When asked whether Mr Johnson was "unsackable" she said they "had a government that was determined to build a government that works for everyone".