Nominations in the race to be the next Lib Dem leader close on Friday at 16:00 BST.
So far two candidates have announced their intention to run – deputy leader Jo Swinson and former Energy and Climate Change Secretary Ed Davey.
Announcing his resignation in March, leader Sir Vince Cable said he wanted to pave the way for “a new generation”.
The winner will be decided by a postal ballot of party members and the results are due to be announced on 23 July.
Candidate hopefuls need support from 10% of the party’s 11 MPs and 200 members from at least 20 local parties.