Labour Shadow Treasury Minister Abena Oppong-Asare claimed a £55 parking fine on her expenses.
She picked up the penalty after claiming a constituency surgery overran.
The Independent Parliamentary Standards Authority (IPSA) investigated the payment.
However, Conservative MPs are calling on Labour leader Sir Keir Starmer to “show leadership” and sack the errant Ms Oppong-Asare.
Sir Iain Duncan Smith said:
“If Starmer doesn’t get rid of her, then taxpayers beware.
‘What a ridiculous claim.
“Why was she allowed to claim it?
“It shows that they have a misplaced sense of entitlement.”
Ms Oppong-Asare only paid the fine after being contact by the Independent newspaper which uncovered the payment.
Labour said the non-payment was an “administrative error” by a member of staff.
IPSA said:
“MPs and their staff are not allowed to claim for penalty charges and fines.
“The rule is clearly stated in the code of conduct for MPs.
“Checks failed in this case to identify that the claim was not allowed.
“It has now been repaid.
“We have changed our process to ensure any future such claims are not paid.”