Three of the five candidates for the next Prime Minister have agreed to publish details of their tax affairs.
May is currently favourite to win the competition, followed by Gove and Leadsom.
They follow in the footsteps of David Cameron and George Osborne, both of whom put out information around their taxes in the aftermath of the Panama Papers scandal.
Liberal Democrat leader Tim Farron has called on all five of the candidates to release documents immediately.
“I have, other leaders have, and I believe these candidates should do so too,” Farron said.
“It took years for Cameron and Osborne to do it. These candidates should do it now. There are no excuses.”
Leadsom was first to endorse the plans on The Andrew Marr Show this morning, and her commitment won support from Labour shadow chancellor John McDonnell.
A spokeswoman for work and pensions secretary Stephen Crabb seperately told City A.M. that he is happy to follow suit, while a spokesman for Liam Fox confirmed that he would do the same in the final round of the competition.