A demanding couple's thank-you note has gone viral after they asked one of their wedding guests to "adjust" the £100 cheque they had been given as a present.

The guest was so shocked at being asked to spend more money, she shared the note on Mumsnet, and got thousands of responses.

Writing under the name "puzzled and pi**ed off" the anonymous user said: "I recently attended an ex-colleague's wedding where, in response to a request for cash gifts, I sent what I thought was a pretty decent cheque (£100 if it matters, though I can't help feeling it shouldn't).

"Last night I received an email which opened with a few comments about how glad they were to see everybody and how generous they'd all been, then said 'we were surprised that your contribution didn't seem to match the warmth of your good wishes on our big day. In view of your own position, if you wanted to send any adjustment it would be thankfully received'.

"For someone who's not easily shocked I confess I'm utterly gobsmacked by this. So as not to drip feed I'll mention that 'your own position' probably refers to a recent inheritance I've had, which maybe they expected something from (and this is an ex-colleague, remember, not a close friend or relative).

"Please, anyone, what do I do now? I've never come across anything like this before and still can't quite believe they've done it – but since they have, should I reply, ring them, ignore it or what??"

Feedback from Mumsnet users included cancelling the first cheque altogether, topping up the cheque with 10p or replying with a rude email, but the anonymous guest said they had eventually replied with: "I assume this is some sort of mistake?"

Given the popularity of the thread on Mumsnet and subsequent publicity the rude email has received, the guest speculated they "probably won't be seeing the bride and groom anytime soon".