The £30,000-a-year bill for renting a dozen fig trees for an MPs' office block has "horrified" Commons Speaker John Bercow.
Bercow accepted the taxpayer was being "fleeced" after finding out the price of the Portcullis House greenery, and said that it must be ended as soon as possible.
The deal has been in place for 12 years and covers care and maintenance of the trees, which shade dining areas in the building's glass-topped atrium.
But Mr Bercow said it should be scrapped immediately, if contractually possible without adding more costs, but no later than September.
In an interview with The House magazine, he said: "I was horrified by it.
"Inevitably and understandably it will cause people out there to think these people are living in another universe.
"I think the contract should absolutely be revisited. If we are going to have trees, they absolutely shouldn't be trees that cause us to fleece the taxpayer in this way, and that must change at the earliest opportunity.
"If there is a contract and it's going to cost us more to get out of it immediately than not, then it may well have to wait.
"But should the present arrangement continue beyond September? Absolutely not."
Mr Bercow also conceded that there were some grounds to argue that the daily prayer session in the Commons was discriminatory.
But though he said he would not stand in the way of a review if sufficient MPs wanted one, he said he wanted to keep what was a "reasonable and generally popular" tradition.
Focus was put on the prayers - which MPs must attend to secure a seat for some high-profile parliamentary sessions - after a court ruled prayers could not be part of local council business.
The ruling does not apply to the Commons, which sets its own rules.
But Mr Bercow said: "If enough Members wanted to look at it, I'm certainly not going to object or try to impose my view.
"Theoretically there is a ground for criticism. But I think that there should be a degree of reasoned, balanced common sense."
The Speaker also called for annual party conferences to be cut to a long weekend so that the Commons could sit without a break from September.
"Most people have an annual holiday entitlement and unless they are taking annual holiday, they will ordinarily be at work in September.
"And I think a lot of our electorate think, given that the MPs finished in the latter part of July, why are they not back at their place of work undertaking their scrutiny, standing up for our interests, debating our concerns, in September? They should be. And frankly I agree with that."