MPs have urged Britain's top 100 firms to donate a day's profits to the rescue fund for victims of the collapsed Farepak Christmas savings scheme.
Farepak customers lost an average of £400 each
The fund has passed the £5m mark, with a £250,000 donation from Barclays bank and £50,000 from Nationwide.
The administrators of the fund have now extended the deadline for donations until 1800 GMT on 29 November.
About 150,000 people are estimated to have lost a total of up to £50m when Farepak collapsed in October.
York-based charity Family Fund set up the Farepak Response Fund earlier this month and hopes to distribute the money to victims by 18 December, probably in the form of vouchers.
Farepak customers are thought to have lost an average of £400 each.
Family Fund chairwoman Shirley Young told the BBC she was aiming to increase the £5m total raised so far substantially:
"Oh I would love to double that, if not more.
"So I'd really implore people out there to join the rest of the people that are giving and put their hands in their pockets.
"You know, I've said that if everybody in the UK gave the equivalent of one present that they would ordinarily buy for a loved one and donated that to the response fund, that would be really, really helpful."
HBOS under fire
The MP's call for donations comes in the form of signatures on a letter, which will be sent to companies in the FTSE 100.
Notable corporate donors so far include the Park Group, Marks & Spencer, Tesco, Morrisons, Argos and Asda.
The Barclays donation came a few days after an MP wrote to the British Bankers' Association, calling on its members to distribute more to the fund.
FAREPAK RESPONSE FUND
Customer losses: Approx £40m
Corporate donations: £5m
Individual donations: £176,671
Donations as at 1130 GMT on 23 November
HBOS has donated £2m, the biggest contribution so far, but has also faced severe criticism for not doing more to help the victims.
It provided the overdraft facility to Farepak's owner, European Home Retail (EHR), and it was an HBOS decision not to extend EHR's overdraft that eventually led to administrators being called in.
However, HBOS and other UK banks are also paying out in the form of refunds to Farepak customers who used credit cards to pay money into the Farepak savings club.
Reports claim that they have been forced to hand OUT more than £1.6m because card contracts allow for refunds when products and services are not delivered or do not match specifications.