Newspaper columnist Simon Heffer has vowed to stand against Commons deputy speaker Sir Alan Haselhurst at the next election unless the MP repays £12,000 in taxpayer-funded gardening.
Mr Heffer, the Daily Telegraph's associate editor, used his column to make the ultimatum.
Conservative Sir Alan, who is Mr Heffer's MP in Saffron Walden, reportedly used his allowances to pay for £12,000-worth of gardening at his country house.
In his column, Mr Heffer said: "If he does not, between now and the opening of nominations for the general election, admit error, apologise, pay back the £12,000 and promise to behave, I shall stand against him as an independent.
"If Sir Alan thinks I am joking, I warn him I am not. I have backers and volunteers. I say this more in anger than in sorrow: we are all angry. Doesn't he get it?"
Labour ministerial aide Rosie Cooper has defended claiming more than £11,000 in expenses to cover legal fees and stamp duty on her second home.
She insisted she had made "appropriate use" of the allowance regime to pay for items including a £99.99 steam cleaner and £5,000 towards repairing decrepit plumbing at her 1930s Westminster flat.
The West Lancashire MP, who is an aide to health minister Ben Bradshaw, has pledged that any profit from the sale of her flat will be returned to the taxpayer.
Tory MP John Greenway spent £500 of taxpayers' money on pot plants and bushes for his garden and £1,900 on redecorating his second home which he sold for a £280,000 profit, the Telegraph has also reported.
He also claimed for a 59p box of matches, two boxes of firelighters worth 99p each, four bags of compost, a trellis and plant food for the London property.
