A politician's "spur of the moment" idea for Comic Relief left her more than £14,000 out of pocket after promising £1 for every retweet she received on Twitter.
Slough MP Fiona Mactaggart, who once spent Red Nose Day dressed as a chicken when she was a teacher, has donated £14,268 to the charity after thousands of people retweeted her post on the social networking site.
The Labour MP admitted she was "a bit" worried as the number of retweets steadily increased after she posted: "I will give £1.00 to Comic relief for every retweet of this message before 9pm."
Ms Mactaggart said she believes generosity "should hurt a bit", and expressed her shock at the difference in charitable giving between rich and poor people.
"I think generosity should hurt a bit and one of the figures that has always shocked me is that poorer people give between 4% and 5% of their income to charity, and richer people give around 2% of their income to charity.
"We should step up to the plate," she said.
The MP received a number of negative tweets suggesting that she would claim the donation back on her expenses - a reaction that annoyed her.
"I was surprised by that, and depressed by it. I had always planned to write a big cheque for Comic Relief. Doing it that way wasn't a carefully planned campaign. I think if it had been it would have cost me a lot more, because people would have been ready to start retweeting as it were.
"I didn't stop to think that people would think somehow that this was a con. Actually, I think we should celebrate generosity.
"I didn't do it for publicity. I didn't stop to think about the fact that people like you would be telephoning me this morning.
"What I thought about was, 'If I do it this way, a lot of people will get Red Nose on their timeline who aren't watching the television but who are looking at other media and maybe they'll give.'
"And actually, lots of them did," she said
The way in which she went about her donation is inkeeping with her belief that people should be "more imaginative" about charitable giving, but she did point out that other politicians could not afford to make such a generous donation.
"It was spur of the moment. I had planned to give all day but doing it that way was spur of the moment," she said.
Adding: "I don't think many politicians can afford to do what I did. But I do think we should be more imaginative about it.
Slough MP Fiona Mactaggart
"Ever since I've been in politics, I've wanted to do something quirky on Red Nose Day. It happens to have to fall on the Friday and so we are not in the chamber in the House of Commons on Red Nose Day.
"When I was a teacher, before I was an MP, I taught for the whole day dressed up as a chicken, and got sponsored for Red Nose Day.
"I am prepared to do peculiar things for this good cause. Maybe this will encourage people to do peculiar things as it were.
"Let me tell you this, I can't afford to do this every year, but maybe next year it will be someone else's turn to think of something," she said.
Ms Mactaggart said the cheque has already been handed over to Comic Relief.
This year's Red Nose Day has raised £75,107,851 so far.