Families of the Birmingham pub bombings victims claim they are having to "beg" for money to fund a legal bid to overturn a coroner's ban on naming suspects.
Peter Thornton QC ruled out the issue of perpetrators at fresh inquests into the deaths of 21 people killed in the double bombings in November 1974, during a hearing last month.
That decision, given as part of a wider ruling by Mr Thornton on what scope the inquests should take, has been "vehemently" opposed by some of the victims' families.
The coroner's decision prompted many of the families, whose campaign had been key in bringing about new inquests into their loved ones' deaths, to announce they would boycott the new hearings, which had been scheduled for later this year.
Julie Hambleton, spokesman for the campaign group Justice4the21, had said that without the prospect of naming the bombers "we may as well not bother having an inquest at all".
Those families are now seeking a judicial review of the coroner's decision in the High Court.
In order to fund the legal work and the application they are now trying to crowd-fund the initial £10,000 - although the total cost of the entire process could be as high as £100,000.
Launching the funding appeal website on Friday, Ms Hambleton said: "We fight for our loved ones, who aren't here to fight for it themselves."
In an emotional plea, she added: "If they were alive and we were dead they too would be standing where we are standing.
"We are now in a position to have to beg for the good people of this country to help us to raise money to fight this challenge in the High Court.
"It is pivotal for us to have a judicial review, and appeal and challenge the coroner's decision to exclude the perpetrators from this inquest.
"Please, please, please, help us to raise the money."
She added: "We have four weeks to raise £10,000.
"If we won't hit our target in four weeks, we get nothing, but the £10,000 is just the beginning.
"We may need £50,000, we may need £100,000, but if we can get the £10,000 and our appeal is accepted by the High Court then we will have all of you out there, who have supported us all these years, to help us continue our fight for truth, justice and accountability.
"We beg you, please help us and thank you all."
Justice4the21 have said they could apply for legal aid funding, but said "experience shows" it would be unlikely to be completed within the deadline for such High Court applications.
The basis of the judicial review application will be to seek a ruling on whether the coroner's decision was compliant and lawful.
The campaigners have said only an inquest which considers what they believe are "the core issues relating to the bomb makers, bomb planters and their associates" will be of any value.
A spokesman for KRW Law, which represents 10 of the families, said: "Any application for legal aid to seek permission to judicially review the decision of the coroner would take excessive time or be rejected in any event.
"Therefore our clients are using crowd-funding to resource this fresh challenge in their quest for truth, justice and accountability on behalf of their loved ones."
:: Donations can be made at www.crowdjustice.com/case/justice4the21/