Thursday is the last day voters in Brecon and Radnorshire can sign a petition which could lead to a by-election after Tory MP Chris Davies was convicted for a false expenses claim.
Mr Davies admitted faking invoices, at Southwark Crown Court, in March and faces a recall petition to keep his seat.
A by-election will be triggered if 10% of the electorate - 5,303 voters - sign it.
The petition closes at 17:00 BST.
The verification of the petition and count will take place at 10:00 on Friday at County Hall in Llandrindod Wells, Powys.
A petition officer will notify House of Commons Speaker John Bercow of the outcome before the result is made public.
Recall petitions are launched when MPs receive a custodial sentence, including suspended sentences, are barred from the Commons for 10 sitting days or are convicted of providing false information about their expenses.