Contractors will soon remove 700 pot plants from MPs' and senators' offices to save up to $132,000 a year.

Department of Parliamentary Services secretary Alan Thompson said he had to find $4 million of savings in his budget of about $115 million, and reluctantly decided the plants had to go when the contract ended next month.

ACT Liberal senator Gary Humphries said the decision upset many politicians, who would be unable to provide their own plants because they could not be watered when Parliament was not sitting.

''I reckon there are lots of Government backbenchers who will be complaining to [Finance Minister] Lindsay Tanner ... I know it is not well received in the building,'' he said.

The owner of Capital Indoor Plant Hire, Ernie Digweed, who has held the contract for Parliament House almost continuously since the 1970s, was dismayed at the decision and politicians had inundated his staff with comments that it was wrong.

Mr Thompson said members and senators were unhappy about the decision, ''but equally they can see that we are on the horns of a dilemma''.

''We have an obligation to stay within budget, and most of the things we are doing we are managing to keep away from affecting general amenity, and they also acknowledge that pot plants are not totally core business for the place.''

Senator Humphries expected ministers would keep their plants, and charge them to their departments.

The decision had put the jobs of up to three of Mr Digweed's staff at risk, and he was concerned it could extend to other agencies.

For more details of this story, including how ministers would retain plants, see today's Canberra Times.